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: a clock shows the time as 9 a. m. if the minute hand gains 7 minutes every hour, how many minutes will the clock gain by 6 p. m. ?
Options: a. 30 min, b. 35 min, c. 63 min, d. 50 min, e. 55 min
Example Output: c

Example Input: Problem: 10, 1000, 100000, 10000000....
Options: a. 100, 000,000, b. 1,000, 000,000, c. 1, 000,000, 000,000, d. 100, e. 1, 000,000
Example Output: b

Example Input: Problem: if 2 ^ 5, 3 ^ 3, and 13 ^ 2 are all factors of the product of 936 and w where w is a positive integer, what is the smallest possible value of w ?
Options: a. 26, b. 39, c. 42, d. 65, e. 156
Example Output:
e