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: 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: the batting average of a particular batsman is 60 runs in 46 innings. if the difference in his highest and lowest score is 140 runs and his average excluding these two innings is 58 runs, find his highest score.
Options: a. 179, b. 367, c. 269, d. 177, e. 174

Ex Output:
e


Ex Input:
Problem: let s be the set of all positive integers that, when divided by 8, have a remainder of 5. what is the 70 th number in this set ?
Options: a. 557, b. 608, c. 613, d. 616, e. 621

Ex Output:

a