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: rs . 900 amounts to rs . 920 in 3 years at simple interest . if the interest is increased by 3 % , it would amount to how much ? 
Options: a ) rs . 1056 , b ) rs . 1001 , c ) rs . 2056 , d ) rs . 1026 , e ) rs . 1856
Example Output: b

Example Input: Problem: the price of a book is increased from $ 300 to $ 480 . what is the % of increase in its price ? 
Options: a ) 10 % , b ) 20 % , c ) 40 % , d ) 50 % , e ) 60 %
Example Output: e

Example Input: Problem: reena took a loan of $ . 1200 with simple interest for as many years as the rate of interest . if she paid $ 192 as interest at the end of the loan period , what was the rate of interest ? 
Options: a ) 3.6 , b ) 6 , c ) 4 , d ) can not be determined , e ) none of these
Example Output:
c