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: a part of certain sum of money is invested at 10 % per annum and the rest at 12 % per annum , if the interest earned in each case for the same period is equal , then ratio of the sums invested is ?
Options: a ) 4 : 2 , b ) 4 : 8 , c ) 4 : 3 , d ) 4 : 0 , e ) 6 : 5

Ex Output:
e

Ex Input:
Problem: a sum was put a simple interest at a certain rate for 1 years . had it been put at 6 % higher rate , it would have fetched rs . 30 more . the sum is :
Options: a ) s . 500 , b ) s . 600 , c ) s . 700 , d ) s . 800 , e ) s . 900

Ex Output:
a