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: the present population of a town is 280 . population increase rate is 10 % p . a . find the population of town after 1 years ? 
Options: a ) 100 , b ) 120 , c ) 200 , d ) 220 , e ) 308

Ex Output:
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: the present population of a town is 2100 . population increase rate is 5 % p . a . find the population of town before 1 years ? 
Options: a ) 1500 , b ) 1600 , c ) 2000 , d ) 2100 , e ) 2500

Ex Output:

c


