If amines are arranged in increasing order of their basic strength in gaseous phase, the correct order will be:
Inductive effect increases basicity.
NH₃ < CH₃NH₂ < (CH₃)₃N < (CH₃)₂NH
NH₃ < (CH₃)₂NH < (CH₃)₃N < CH₃NH₂
(CH₃)₃N < (CH₃)₂NH < CH₃NH₂ < NH₃
NH₃ < CH₃NH₂ < (CH₃)₂NH < (CH₃)₃N
Basicity increases with more alkyl groups due to the +I effect in gaseous phase.

Study the diagram above and answer the following questions:
(a) How many alleles are involved in blood grouping?
(b) A person having 'AB' blood group has both dominant alleles. What is this inheritance type called?
(c) A man with 'A' blood group marries a woman with 'B' blood group. Can they have a child with 'O' blood group? Explain with the help of a cross.