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: a reduction of 20 % in the price of salt enables a lady to obtain 10 kgs more for rs . 400 , find the original price per kg ? 
Options: a ) s . 7 , b ) s . 9 , c ) s . 10 , d ) s . 11 , e ) s . 19
Example Output: c

Example Input: Problem: the banker ' s gain on a sum due 6 years hence at 12 % per annum is rs . 900 . what is the banker ' s discount ? 
Options: a ) 1240 , b ) 1120 , c ) 1190 , d ) 2150 , e ) none of these
Example Output: d

Example Input: Problem: at what rate percent per annum will a sum of money double in 16 years ? 
Options: a ) 10.6 % , b ) 3.65 % , c ) 6.25 % , d ) 8.32 % , e ) 11 %
Example Output:
c