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 family made a down payment of $ 300 and borrowed the balance on a set of encyclopedias that cost $ 750 . the balance with interest was paid in 9 monthly payments of $ 57 each and a final payment of $ 21 . the amount of interest paid was what percent of the amount borrowed ? 
Options: a ) 6 % , b ) 12 % , c ) 14 % , d ) 18.66 % , e ) 20 %
Example Output: d

Example Input: Problem: the simple interest on rs . 20 for 6 months at the rate of 5 paise per rupeeper month is 
Options: a ) 1.2 , b ) 1.4 , c ) 6 , d ) 7 , e ) none
Example Output: c

Example Input: Problem: the principal that amounts to rs . 4813 in 3 years at 6 1 / 4 % per annum c . i . compounded annually , is ? 
Options: a ) s . 3096 , b ) s . 4036 , c ) s . 4085 , d ) s . 4096 , e ) s . 5096
Example Output:
b