Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.

Ex Input:
Problem: in n is a positive integer less than 200, and 14 n / 60 is an integer, then n has how many different positive prime factors s ?
Options: a. 2, b. 3, c. 5, d. 6, e. 8

Ex Output:
b

Ex Input:
Problem: find the maximum value of the function f ( x ) = x 5 if x is a number between - 5 and 13.
Options: a. 6, b. 7, c. 8, d. 9, e. none

Ex Output:
c

Ex Input:
Problem: find the ratio in which rice at rs. 7.10 a kg be mixed with rice at rs. 5.70 a kg to produce a mixture worth rs. 6.30 a kg ?
Options: a. 1: 3, b. 2: 3, c. 3: 4, d. 4: 5, e. none of these

Ex Output:
c