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: some of 50 % - intensity red paint is replaced with 20 % solution of red paint such that the new paint intensity is 40 % . what fraction of the original paint was replaced ? 
Options: a ) 1 / 3 , b ) 1 / 5 , c ) 2 / 3 , d ) 3 / 4 , e ) 4 / 5

Ex Output:
a


Ex Input:
Problem: in how many years will a sum of money doubles itself at 12 % per annum on simple interest ? 
Options: a ) 15 % , b ) 20 % , c ) 10 % , d ) 8 % , e ) 22 %

Ex Output:
d


Ex Input:
Problem: if the true discount on a sum due 2 years hence at 14 % per annum be rs . 168 , the sum due is : 
Options: a ) rs . 768 , b ) rs . 968 , c ) rs . 1960 , d ) rs . 2400 , e ) none

Ex Output:

a