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: the annual interest rate earned by an investment increased by 8 percent from last year to this year . if the annual interest rate earned by the investment this year was 27 percent , what was the annual interest rate last year ? 
Options: a ) 22 % , b ) 20 % , c ) 25 % , d ) 23 % , e ) 21 %

Ex Output:
c


Ex Input:
Problem: how many liters of a 40 % iodine solution need to be mixed with 35 liters of a 20 % iodine solution to create a 32 % iodine solution ? 
Options: a ) 35 , b ) 49 , c ) 100 , d ) 102 , e ) 140

Ex Output:
d


Ex Input:
Problem: if the selling price of 50 articles is equal to the cost price of 20 articles , then the loss or gain percent is : 
Options: a ) 45 % , b ) 23 % , c ) 20 % , d ) 60 % , e ) 56 %

Ex Output:

d