In this task, you need to answer the given multiple-choice question on the gain. Gain is the value by which to multiply the input. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Example Input: Problem: if a large pizza has a radius that is 10 % larger that that of a medium pizza , what is the percent increase in area between a medium and a large pizza ? 
Options: a ) 15 % , b ) 21 % , c ) 25 % , d ) 30 % , e ) 36 %
Example Output: b

Example Input: Problem: in an office in singapore there are 60 % female employees . 50 % of all the male employees are computer literate . if there are total 62 % employees computer literate out of total 1100 employees , then the no . of female employees who are computer literate ? 
Options: a ) 462 , b ) 674 , c ) 672 , d ) 960 , e ) none
Example Output: a

Example Input: Problem: machine a produces 100 parts thrice as fast as machine b does . machine b produces 100 parts in 30 minutes . if each machine produces parts at a constant rate , how many parts does machine a produce in 6 minutes ? 
Options: a ) 20 , b ) 80 , c ) 40 , d ) 60 , e ) 50
Example Output:
d