In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Ex Input:
Problem: if x ^ 2 + y ^ 2 = 15 and xy = 3 , then ( x − y ) ^ 2 = 
Options: a ) 8 , b ) 9 , c ) 14 , d ) 17 , e ) 20

Ex Output:
b


Ex Input:
Problem: a ’ s speed is 20 / 19 times that of b . if a and b run a race , what part of the length of the race should a give b as a head start , so that the race ends in a dead heat ? 
Options: a ) 1 / 19 , b ) 3 / 19 , c ) 1 / 10 , d ) 1 / 20 , e ) 3 / 10

Ex Output:
d


Ex Input:
Problem: how many positive integers between 1 and 400 are there such that they are multiples of 25 ? 
Options: a ) 12 , b ) 13 , c ) 16 , d ) 15 , e ) 11

Ex Output:

c