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.

Example Input: Problem: buses a and b start from a common bus stop x. bus a begins to travel in a straight line away from bus b at a constant rate of 20 miles per hour. one hour later, bus b begins to travel in a straight line in the exact opposite direction at a constant rate of 80 miles per hour. if both buses travel indefinitely, what is the positive difference, in minutes, between the amount of time it takes bus b to cover the exact distance that bus a has covered and the amount of time it takes bus b to cover twice the distance that bus a has covered ?
Options: a. 36, b. 72, c. 132, d. 144, e. 180
Example Output: c

Example Input: Problem: the area of one square is x ^ 2 + 4 x + 4 and the area of another square is 4 x ^ 2 − 12 x + 9. if the sum of the perimeters of both squares is 32, what is the value of x ?
Options: a. 0, b. 2, c. 2.5, d. 4.67, e. 3
Example Output: e

Example Input: Problem: if ( m - 8 ) is a factor of m ^ 2 - hm - 24, then h =
Options: a. 3, b. 5, c. 6, d. 11, e. 16
Example Output:
b