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 5 a = 3125, then the value of 5 ( a - 3 ) is :
Options: a. 25, b. 125, c. 625, d. 1625, e. none of these
Example Output: a

Example Input: Problem: if x ^ 2 – 3 x = 18, then one possible value of x – 4 =
Options: a. - 9, b. - 5, c. - 3, d. - 1, e. 2
Example Output: e

Example Input: Problem: dan can do a job alone in 12 hours. annie, working alone, can do the same job in just 9 hours. if dan works alone for 8 hours and then stops, how many hours will it take annie, working alone, to complete the job ?
Options: a. 2, b. 3, c. 4, d. 5, e. 6
Example Output:
b