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: a can complete a certain job in 19 days . b is 90 % more efficient than a . in how many days can b complete the same job ?
Options: a ) 6 , b ) 6.25 , c ) 7 , d ) 7.5 , e ) 10
Example Output: e

Example Input: Problem: how many pounds of salt at 50 cents / lb must be mixed with 40 lbs of salt that costs 25 cents / lb so that a merchant will get 20 % profit by selling the mixture at 48 cents / lb ?
Options: a ) 20 , b ) 15 , c ) 40 , d ) 60 , e ) 25
Example Output: d

Example Input: Problem: if a large pizza has a radius that is 50 % larger that that of a medium pizza , what is the percent increase in area between a medium and a large pizza ?
Options: a ) 25 % , b ) 50 % , c ) 75 % , d ) 125 % , e ) 150 %
Example Output:
d