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 3 - digit numbers are divisible by 6 in all ?
Options: a ) 149 , b ) 150 , c ) 151 , d ) 166 , e ) none

Ex Output:
b

Ex Input:
Problem: the sum of all the integers k such that 25 < k < 24 is
Options: a ) 0 , b ) - 2 , c ) - 25 , d ) - 49 , e ) - 47

Ex Output:
e

Ex Input:
Problem: the smallest value of n , for which 2 n + 1 is not a prime number , is
Options: a ) 3 , b ) 4 , c ) 5 , d ) none , e ) 6

Ex Output:
b