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'.

Input: Consider Input: Problem: in n is a positive integer less than 200 , and 18 n / 60 is an integer , then n has how many different positive prime factors ? 
Options: a ) 2 , b ) 3 , c ) 5 , d ) 6 , e ) 8

Output: a


Input: Consider Input: Problem: the unit digit in the product ( 784 x 618 x 917 x 463 ) is : 
Options: a ) 5 , b ) 9 , c ) 16 , d ) 2 , e ) 42

Output: d


Input: Consider Input: Problem: how many multiples of 2 are there between 1 and 52 , exclusive ? 
Options: a ) 21 , b ) 22 , c ) 25 , d ) 26 , e ) 28


Output: c