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'.

Ex 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

Ex Output:
a


Ex Input:
Problem: after decreasing 40 % in the price of an article costs rs . 1050 . find the actual cost of an article ? 
Options: a ) 1200 , b ) 1750 , c ) 1050 , d ) 1570 , e ) 1005

Ex Output:
b


Ex Input:
Problem: a present value of a machine is $ 800 . its value depletion rate is 10 % per annum then find the machine value after 2 years ? 
Options: a ) $ 900 , b ) $ 810 , c ) $ 915 , d ) $ 715 , e ) $ 648

Ex Output:

e