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: what is the units digit of 32 ! + 50 ! + 4 ! + 4 ! ?
Options: a. 0, b. 2, c. 4, d. 6, e. 8

Ex Output:
e


Ex Input:
Problem: aaron will jog from home at 2 miles per hour and then walk back home by the same route at 4 miles per hour. how many miles from home can aaron jog so that he spends a total of 3 hours jogging and walking ?
Options: a. 5, b. 7, c. 3, d. 9, e. 10

Ex Output:
c


Ex Input:
Problem: a computer is programmed to multiply consecutive even integers 2 * 4 * 6 * 8 * … * n until the product is divisible by 1881, what is the value of n ?
Options: a. 22, b. 38, c. 114, d. 122, e. 672

Ex Output:

c