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: in an acoustics class , 120 students are male and 100 students are female . 25 % of the male students and 20 % of the female students are engineering students . 20 % of the male engineering students and 25 % of the female engineering students passed the final exam . what percentage of engineering students passed the exam ? 
Options: a ) 5 % , b ) 10 % , c ) 16 % , d ) 22 % , e ) none of these
Example Output: d

Example Input: Problem: a sum of money at simple interest amounts to rs . 815 in 3 years and to rs . 865 in 4 years . the sum is : 
Options: a ) s . 665 , b ) s . 690 , c ) s . 698 , d ) s . 700 , e ) s . 720
Example Output: a

Example Input: Problem: a sum fetched a total simple interest of 4025.25 at the rate of 9 % . p . a . in 5 years . what is the sum ? 
Options: a ) 5768 , b ) 8925 , c ) 2345 , d ) 8945 , e ) 8723
Example Output:
d