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: find the ones digit of 73 ^ 356 
Options: a ) 1 , b ) 5 , c ) 6 , d ) 7 , e ) 9

Ex Output:
a


Ex Input:
Problem: the average age of a group of 10 persons was decreased by 3 years when one person , whose age was 42 years , was replaced by a new person . find the age of the new person ? 
Options: a ) 22 , b ) 18 , c ) 12 , d ) 88 , e ) 66

Ex Output:
c


Ex Input:
Problem: what could be the range of a set consisting of odd multiples of 7 ? 
Options: a ) 21 , b ) 24 , c ) 35 , d ) 62 , e ) 70

Ex Output:

e