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: if x ^ 2 – 4 x = 5, then one possible value of x – 2 =
Options: a. - 9, b. - 5, c. - 3, d. - 1, e. 5
Example Output: c

Example Input: Problem: trapezoid jklm in the x - y plane has coordinates j = ( – 3, – 4 ), k = ( – 3, 1 ), l = ( 5, 7 ), and m = ( 5, – 4 ). what is its perimeter ?
Options: a. 34, b. 36, c. 38, d. 40, e. ( f ) 42
Example Output: a

Example Input: Problem: what is the sum of the greatest common factor and the lowest common multiple of 16 and 72 ?
Options: a. 142, b. 152, c. 124, d. 160, e. 184
Example Output:
b