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'.

Example Input: Problem: a = 4 ^ 15 - 625 ^ 3 and a / x is an integer , where x is a positive integer greater than 1 , such that it does not have a factor p such that 1 < p < x , then how many different values for x are possible ? 
Options: a ) none , b ) one , c ) two , d ) three , e ) four
Example Output: c

Example Input: Problem: if the sales tax reduced from 3 1 / 2 % to 3 1 / 3 % , then what difference does it make to a person who purchases an article with market price of rs . 10800 ? 
Options: a ) 11 , b ) 13 , c ) 14 , d ) 18 , e ) 10
Example Output: d

Example Input: Problem: the average of first 6 natural numbers is ? 
Options: a ) 5.2 , b ) 3.5 , c ) 5.3 , d ) 5.9 , e ) 5.1
Example Output:
b