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: the annual interest rate earned by an investment increased by 11 percent from last year to this year . if the annual interest rate earned by the investment this year was 22 percent , what was the annual interest rate last year ? 
Options: a ) 17 % , b ) 19 % , c ) 18 % , d ) 20 % , e ) 22 %
Example Output: d

Example Input: Problem: the cost price of a radio is rs . 2550 and it was sold for rs . 2130 , find the loss % ? 
Options: a ) 18 , b ) 10 , c ) 15 , d ) 66 , e ) 41
Example Output: c

Example Input: Problem: what is 15 percent of 68 ? 
Options: a ) 7.6 , b ) 8.7 , c ) 9.1 , d ) 10.2 , e ) 11.6
Example Output:
d