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 person borrows rs . 5000 for 2 years at 4 % p . a . simple interest . he immediately lends it to another person at 8 % p . a for 2 years . find his gain in the transaction per year . 
Options: a ) 167.5 , b ) 150 , c ) 200 , d ) 112.5 , e ) 212.5
Example Output: c

Example Input: Problem: on a sum of money , the simple interest for 2 years is rs . 324 , while the compound interest is rs . 340 , the rate of interest being the same in both the cases . the rate of interest is 
Options: a ) 15 % , b ) 14.25 % , c ) 9.87 % , d ) 10.5 % , e ) 11.5 %
Example Output: c

Example Input: Problem: in how many years rs 200 will produce the same interest at 10 % as rs . 400 produce in 5 years at 12 % 
Options: a ) 16 , b ) 13 , c ) 12 , d ) 14 , e ) 15
Example Output:
c