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 the simple interest on a sum of money for 4 years at 8 % per annum is rs . 560 , what is the compound interest on the same sum at the rate and for the same time ? 
Options: a ) rs . 640.86 , b ) rs . 430.86 , c ) rs . 330.86 , d ) rs . 630.86 , e ) rs . 130.86
Example Output: d

Example Input: Problem: today joelle opened an interest - bearing savings account and deposited $ 7,000 . if the annual interest rate is 5 percent compounded interest , and she neither deposits nor withdraws money for exactly 2 years , how much money will she have in the account ? 
Options: a ) $ 7727.50 , b ) $ 7717.50 , c ) $ 7737.50 , d ) $ 7747.50 , e ) $ 7757.50
Example Output: b

Example Input: Problem: the banker ' s gain of a certain sum due 2 years hence at 10 % per annum is rs . 24 . what is the present worth ? 
Options: a ) rs . 600 , b ) rs . 500 , c ) rs . 400 , d ) rs . 300 , e ) none of these
Example Output:
a