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: the cost price of an article is 70 % of the marked price . calculate the gain percent after allowing a discount of 10 % . 
Options: a ) 13.6 % , b ) 28.6 % , c ) 35.6 % , d ) 42.3 % , e ) none
Example Output: b

Example Input: Problem: a sum fetched a total simple interest of $ 4061.25 at the rate of 9 p . c . p . a . in 5 years . what is the sum ? 
Options: a ) $ 8829 , b ) $ 2840 , c ) $ 6578 , d ) $ 7782 , e ) $ 8926
Example Output: e

Example Input: Problem: sonika deposited rs . 13000 which amounted to rs . 10200 after 4 years at simple interest . had the interest been 5 % more . she would get how much ? 
Options: a ) 18990 , b ) 13002 , c ) 12800 , d ) 12300 , e ) 14500
Example Output:
c