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: how many numbers from 19 to 79 are exactly divisible by 11 ? 
Options: a ) 5 , b ) 6 , c ) 9 , d ) 11 , e ) 12

Ex Output:
b


Ex Input:
Problem: when positive integer x is divided by positive integer y , the remainder is 9 . if x / y = 96.12 , what is the value of y ? 
Options: a ) 96 , b ) 75 , c ) 48 , d ) 25 , e ) 12

Ex Output:
b


Ex Input:
Problem: when a person aged 39 is added to a group of n people , the average age increases by 2 . when a person aged 15 is added instead , the average age decreases by 1 . what is the value of r ? 
Options: a ) 7 , b ) 8 , c ) 9 , d ) 10 , e ) 11

Ex Output:

a