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 profits of qrs company rose 10 % from march to april , then dropped 20 % from april to may , then rose 50 % from may to june . what was the percent increase for the whole quarter , from march to june ? 
Options: a ) 15 % , b ) 32 % , c ) 40 % , d ) 62 % , e ) 80 %
Example Output: b

Example Input: Problem: the value of a machine depreciates at the rate of 10 % every year . it was purchased 3 years ago . if its present value is rs 8,748 , its purchase price was ? 
Options: a ) rs 16,000 , b ) rs 18,000 , c ) rs 12,000 , d ) rs 14,000 , e ) none of these
Example Output: c

Example Input: Problem: a sum of money at simple interest amounts to rs . 825 in 3 years and to rs . 854 in 4 years . the sum is ? 
Options: a ) rs . 738 , b ) rs . 638 , c ) rs . 650 , d ) rs . 730 , e ) rs . 735
Example Output:
a