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: if a and b get profits of rs . 18,000 and rs . 15,000 respectively at the end of year then ratio of their investments are 
Options: a ) 6 : 5 , b ) 1 : 4 , c ) 3 : 2 , d ) 2 : 3 , e ) 2 : 5
Example Output: a

Example Input: Problem: the price of a t . v . set worth rs . 40000 is to be paid in 20 installments of rs . 1000 each . if the rate of interest be 6 % per annum , and the first installment be paid at the time of purchase , then the value of the last installment covering the interest as well will be ? 
Options: a ) 22678 , b ) 26699 , c ) 26788 , d ) 19000 , e ) 39000
Example Output: e

Example Input: Problem: a bookseller sells his books at a 25 % markup in price . if he sells a book for $ 12.5 , how much did he pay for it ? 
Options: a ) $ 14.40 , b ) $ 14.00 , c ) $ 11.00 , d ) $ 9.60 , e ) $ 10.00
Example Output:
e