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'.

Ex Input:
Problem: in a certain pond , 80 fish were caught , tagged , and returned to the pond . a few days later , 50 fish were caught again , of which 2 were found to have been tagged . if the percent of tagged fish in the second catch approximates the percent of tagged fish in the pond , what is the approximate number of fish in the pond ? 
Options: a ) 400 , b ) 625 , c ) 1,250 , d ) 2,000 , e ) 10,000

Ex Output:
d


Ex Input:
Problem: michelle deposited a certain sum of money in a savings account on july 1 st , 2007 . she earns an 12 % interest compounded semiannually . the sum of money in the account on december 31 st , 2009 is approximately what percent of the initial deposit ? 
Options: a ) 117 % , b ) 120 % , c ) 121 % , d ) 133 % , e ) 140 %

Ex Output:
d


Ex Input:
Problem: a candidate appearing for an examination has to secure 55 % marks to pass paper i . but he secured only 45 marks and failed by 25 marks . what is the maximum mark for paper i ? 
Options: a ) 127 , b ) 120 , c ) 130 , d ) 140 , e ) 150

Ex Output:

a