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 shopkeeper has 280 kg of apples . he sells 85 % of these at 20 % profit and remaining 60 % at 30 % profit . find his % profit on total . 
Options: a ) 24 % , b ) 25 % , c ) 26 % , d ) 28 % , e ) 35 %
Example Output: e

Example Input: Problem: find the compound interest on $ 800 for 1 year at 10 % p . a . if ci is component yearly ? 
Options: a ) $ 40 , b ) $ 400 , c ) $ 840 , d ) $ 800 , e ) $ 80
Example Output: a

Example Input: Problem: a bookstore has a shelf that contains biographies which normally sell for $ 20 each and mysteries that normally sell for $ 12 each . during a sale , the biographies and mysteries are discounted at different rates so that a customer saves a total of $ 19 from the normal price by buying 5 discounted biographies and 3 discounted mysteries . if the sum of the discount rates for the two types of books is 43 percent , what is the discount rate on mysteries ? 
Options: a ) 24 % , b ) 25 % , c ) 30 % , d ) 37.5 % , e ) 40 %
Example Output:
d