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: 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
Example Output: a

Example Input: Problem: $ 350 is divided among a , b , and c so that a receives half as much as b , and b receives half as much as c . how much money is c ' s share ? 
Options: a ) $ 200 , b ) $ 225 , c ) $ 250 , d ) $ 275 , e ) $ 300
Example Output: c

Example Input: Problem: how many positive integers less than 10,000 are there in which the sum of the digits equals 5 ? 
Options: a ) 31 , b ) 51 , c ) 56 , d ) 62 , e ) 93
Example Output:
c