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 40 % of a certain number is 160 , then what is 90 % of that number ? 
Options: a ) 270 , b ) 380 , c ) 260 , d ) 360 , e ) 290
Example Output: d

Example 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
Example Output: d

Example Input: Problem: rs 60000 is divided into two parts one part is given to a person with 10 % interest and another part is given to a person with 20 % interest . at the end of first year he gets profit 7000 find money given by 10 % ? 
Options: a ) 30000 , b ) 40000 , c ) 50000 , d ) 60000 , e ) 70000
Example Output:
b