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: in an examination it is necessary for a candidate to get 45 % of the maximum marks to pass . a candidate who gets 180 marks , fails by 45 marks . find the maximum marks . 
Options: a ) 450 , b ) 600 , c ) 500 , d ) 550 , e ) 650

Ex Output:
c


Ex Input:
Problem: how long will a boy take to run round a square field of side 50 meters , if he runs at the rate of 10 km / hr ? 
Options: a ) 52 sec , b ) 45 sec , c ) 72 sec , d ) 25 sec , e ) 39 sec

Ex Output:
c


Ex Input:
Problem: what is 120 % of 13 / 24 of 600 ? 
Options: a ) 320 , b ) 390 , c ) 440 , d ) 480 , e ) 510

Ex Output:

b