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 population of a town is 10000 . it increases annually at the rate of 20 % p . a . what will be its population after 1 year ?
Options: a ) 12300 , b ) 12350 , c ) 12000 , d ) 12500 , e ) 12600

Ex Output:
c

Ex Input:
Problem: in order to obtain an income of rs . 1000 from 50 % stock at rs . 500 , one must make an investment of
Options: a ) rs . 17000 , b ) rs . 16050 , c ) rs . 15400 , d ) rs . 10000 , e ) rs . 10500

Ex Output:
d

Ex Input:
Problem: a person spent rs . 8,550 from his salary on food and 8,640 on house rent . after that he was left with 40 % of his monthly salary . what is his monthly salary ?
Options: a ) 38,650 , b ) 28,650 , c ) 48,650 , d ) 68,650 , e ) 18,650

Ex Output:
b