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: in a division , a student took 72 as divisor instead of 36 . his answer was 24 . the correct answer is - 
Options: a ) 42 , b ) 32 , c ) 48 , d ) 28 , e ) 38

Ex Output:
c


Ex Input:
Problem: what is the average of first 21 multiples of 5 ? 
Options: a ) a ) 70 , b ) b ) 77 , c ) c ) 55 , d ) d ) 81 , e ) e ) 82

Ex Output:
c


Ex Input:
Problem: what least number must be subtracted from 9679 so that the remaining number is divisible by 15 ? 
Options: a ) 3 , b ) 1 , c ) 16 , d ) 4 , e ) 15

Ex Output:

d