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 difference between c . i . and s . i . on an amount of rs . 15,000 for 2 years is rs . 24 . what is the rate of interest per annum ?
Options: a ) 8 , b ) 2 , c ) 9 , d ) 4 , e ) 6
Example Output: d

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 person bought 129 glass bowls at a rate of rs . 11 per bowl . he sold 118 of them at rs . 15 and the remaining broke . what is the percentage gain for a ?
Options: a ) 40 , b ) 2900 / 129 , c ) 2430 / 70 , d ) 2791 / 11 , e ) 2719 / 8
Example Output:
b