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: raman ' s salary was decreased by 50 % and subsequently increased by 50 % . how much percent does he loss . 
Options: a ) 75 , b ) 65 , c ) 45 , d ) 25 , e ) 85
Example Output: d

Example Input: Problem: a man took a loan at rate of 12 % per annum simple interest . after 3 years he had to pay 5400 interest . the principal amount borrowed by him was . 
Options: a ) rs 14000 , b ) rs 15000 , c ) rs 16000 , d ) rs 17000 , e ) none of these
Example Output: b

Example Input: Problem: a shoe merchant has declared a 10 % rebate in prices . how much rebate would one get if he purchases 5 pairs of shoes at rs . 28 each ? 
Options: a ) 11 , b ) 12 , c ) 13 , d ) 14 , e ) 15
Example Output:
d