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: walking 7 / 6 of his usual rate , a boy reaches his school 3 min early . find his usual time to reach the school ? 
Options: a ) 21 , b ) 28 , c ) 99 , d ) 77 , e ) 66
Example Output: a

Example Input: Problem: a cycle is bought for rs . 1120 and sold for rs . 1200 , find the gain percent ? 
Options: a ) 7 % , b ) 2 % , c ) 6 % , d ) 1 % , e ) 8 %
Example Output: a

Example Input: Problem: solution y is 30 percent liquid x and 70 percent water . if 2 kilograms of water evaporate from 10 kilograms of solution y and 2 kilograms of solution y are added to the remaining 6 kilograms of liquid , what percent of this new solution is liquid x ? 
Options: a ) 34 , b ) 35 , c ) 36 , d ) 37 1 / 25 , e ) 40
Example Output:
c