As we can clearly observe in the numerator, the numerator of the previous term is multiplied by 2 and 1 is added. So numerator will be 9(2)+1=19
Similarly, denominator of the previous term is multiplied by 2 and then 2 is added. So 20(2)+2=42
Hence the fraction will be 19/42
The correct answer is (B) : 19/42