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'.

Ex Input:
Problem: an error 10 % in excess is made while measuring the side of a square . now what is the percentage of error in the calculated area of the square ? 
Options: a ) 6.64 % , b ) 16.64 % , c ) 15.64 % , d ) 21 % , e ) 10.64 %

Ex Output:
d


Ex Input:
Problem: a car is purchased on hire - purchase . the cash price is $ 26 000 and the terms are a deposit of 10 % of the price , then the balance to be paid off over 60 equal monthly installments . interest is charged at 12 % p . a . what is the monthly installment ? 
Options: a ) $ 603 , b ) $ 624 , c ) $ 625 , d ) $ 626 , e ) $ 627

Ex Output:
b


Ex Input:
Problem: shopkeeper rise price by 31 % and gives successive discount of 10 % and 15 % . what is overall % gain or loss ? 
Options: a ) 0.215 % , b ) 1.215 % , c ) 3.215 % , d ) 6.215 % , e ) 7.215 %

Ex Output:

a