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: if a and b get profits of rs . 18,000 and rs . 15,000 respectively at the end of year then ratio of their investments are
Options: a ) 6 : 5 , b ) 1 : 4 , c ) 3 : 2 , d ) 2 : 3 , e ) 2 : 5

Ex Output:
a

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: if the cost price of 50 articles is equal to the selling price of 20 articles , then the gain or loss percent is ?
Options: a ) 16 , b ) 127 , c ) 12 , d ) 18 , e ) 150

Ex Output:
e