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: at what rate of compound interest per annum will a sum of rs . 1200 become rs . 1348.32 in 2 years 
Options: a ) 3 % , b ) 4 % , c ) 5 % , d ) 6 % , e ) 7 %
Example Output: d

Example Input: Problem: a part of certain sum of money is invested at 10 % per annum and the rest at 12 % per annum , if the interest earned in each case for the same period is equal , then ratio of the sums invested is ? 
Options: a ) 4 : 2 , b ) 4 : 8 , c ) 4 : 3 , d ) 4 : 0 , e ) 6 : 5
Example Output: e

Example Input: Problem: the true discount on a bill of rs . 270 is rs . 45 . the banker ' s discount is 
Options: a ) 54 , b ) 55 , c ) 56 , d ) 57 , e ) none of these
Example Output:
a