From IV: A, B, C, and D have one long-term contract each: 3, 7, 3, and 4 years respectively. All other contracts are one-year contracts.
From I, Z has at least one contract every year. The only possible combinations are 7+3 or 7+4 years, with the 7-year contract being from B.
From III, Vendor W had contracts only in 2012. From VII, Institutes B and D each had exactly one contract in 2012, meaning W received contracts from A and C.
From II, Vendor X had contracts every year up to 2015 but none after that. From VI and VII, C and D had no contracts in 2011 and 2010 respectively. Thus, A must have had a 3-year contract with X from 2010-2012. For 2013-2015, X could not have a contract with B, so it must be with either C or D.
Now, the table looks like:
2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | |
A | X | X | X,W | N | N | N | N | N | N | N |
B | Z,Y | Z | Z | Z | Z | Z | Z | N | N | N |
C | N | N | W | N | N | N | N | Z | Z | Z |
D | N | N | X | X | X | X | N | N | N | Y |
N' represents no contract. Among the given options, only the year 2015 has two contracts, while the rest have only one contract in that year.
So, the correct option is (C): 2015
From IV: A, B, C, and D have one long-term contract each: 3, 7, 3, and 4 years respectively. All other contracts are one-year contracts.
From I, Z has at least one contract every year. The only possible combinations are 7+3 or 7+4 years, with the 7-year contract being from B.
From III, Vendor W had contracts only in 2012. From VII, Institutes B and D each had exactly one contract in 2012, meaning W received contracts from A and C.
From II, Vendor X had contracts every year up to 2015 but none after that. From VI and VII, C and D had no contracts in 2011 and 2010 respectively. Thus, A must have had a 3-year contract with X from 2010-2012. For 2013-2015, X could not have a contract with B, so it must be with either C or D.
Now, the table looks like:
2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | |
A | X | X | X,W | N | N | N | N | N | N | N |
B | Z,Y | Z | Z | Z | Z | Z | Z | N | N | N |
C | N | N | W | N | N | N | N | Z | Z | Z |
D | N | N | X | X | X | X | N | N | N | Y |
N' represents no contract.
So, the correct option is (A): D had a contract with Y in 2019
From IV: A, B, C, and D have one long-term contract each: 3, 7, 3, and 4 years respectively. All other contracts are one-year contracts.
From I, Z has at least one contract every year. The only possible combinations are 7+3 or 7+4 years, with the 7-year contract being from B.
From III, Vendor W had contracts only in 2012. From VII, Institutes B and D each had exactly one contract in 2012, meaning W received contracts from A and C.
From II, Vendor X had contracts every year up to 2015 but none after that. From VI and VII, C and D had no contracts in 2011 and 2010 respectively. Thus, A must have had a 3-year contract with X from 2010-2012. For 2013-2015, X could not have a contract with B, so it must be with either C or D.
Now, the table looks like:
2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | |
A | X | X | X,W | N | N | N | N | N | N | N |
B | Z,Y | Z | Z | Z | Z | Z | Z | N | N | N |
C | N | N | W | N | N | N | N | Z | Z | Z |
D | N | N | X | X | X | X | N | N | N | Y |
'N' represents no contract. Only during 2016, 2017 and 2018 there was only 1 contract.
So, the correct option is (C): 3.
From IV: A, B, C, and D have one long-term contract each: 3, 7, 3, and 4 years respectively. All other contracts are one-year contracts.
From I, Z has at least one contract every year. The only possible combinations are 7+3 or 7+4 years, with the 7-year contract being from B.
From III, Vendor W had contracts only in 2012. From VII, Institutes B and D each had exactly one contract in 2012, meaning W received contracts from A and C.
From II, Vendor X had contracts every year up to 2015 but none after that. From VI and VII, C and D had no contracts in 2011 and 2010 respectively. Thus, A must have had a 3-year contract with X from 2010-2012. For 2013-2015, X could not have a contract with B, so it must be with either C or D.
Now, the table looks like:
2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | |
A | X | X | X,W | N | N | N | N | N | N | N |
B | Z,Y | Z | Z | Z | Z | Z | Z | N | N | N |
C | N | N | W | N | N | N | N | Z | Z | Z |
D | N | N | X | X | X | X | N | N | N | Y |
'N' represents no contract. and the number of contracts in 2010 is 3.
So, the correct option is (C): 3.
From IV: A, B, C, and D have one long-term contract each: 3, 7, 3, and 4 years respectively. All other contracts are one-year contracts.
From I, Z has at least one contract every year. The only possible combinations are 7+3 or 7+4 years, with the 7-year contract being from B.
From III, Vendor W had contracts only in 2012. From VII, Institutes B and D each had exactly one contract in 2012, meaning W received contracts from A and C.
From II, Vendor X had contracts every year up to 2015 but none after that. From VI and VII, C and D had no contracts in 2011 and 2010 respectively. Thus, A must have had a 3-year contract with X from 2010-2012. For 2013-2015, X could not have a contract with B, so it must be with either C or D.
Now, the table looks like:
2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | |
A | X | X | X,W | N | N | N | N | N | N | N |
B | Z,Y | Z | Z | Z | Z | Z | Z | N | N | N |
C | N | N | W | N | N | N | N | Z | Z | Z |
D | N | N | X | X | X | X | N | N | N | Y |
'N' represents no contract. A and B have multiple contract in a same year.
So, the correct option is (D): A and B only.
From IV: A, B, C, and D have one long-term contract each: 3, 7, 3, and 4 years respectively. All other contracts are one-year contracts.
From I, Z has at least one contract every year. The only possible combinations are 7+3 or 7+4 years, with the 7-year contract being from B.
From III, Vendor W had contracts only in 2012. From VII, Institutes B and D each had exactly one contract in 2012, meaning W received contracts from A and C.
From II, Vendor X had contracts every year up to 2015 but none after that. From VI and VII, C and D had no contracts in 2011 and 2010 respectively. Thus, A must have had a 3-year contract with X from 2010-2012. For 2013-2015, X could not have a contract with B, so it must be with either C or D.
Now, the table looks like:
2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | |
A | X | X | X,W | N | N | N | N | N | N | N |
B | Z,Y | Z | Z | Z | Z | Z | Z | N | N | N |
C | N | N | W | N | N | N | N | Z | Z | Z |
D | N | N | X | X | X | X | N | N | N | Y |
'N' represents no contract. A, B, W, X had more than one contracts in a single year.
So, the correct option is (D): A, B, W, and X.