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: 6 men and 8 women can complete a work in 10 days. 26 men and 48 women can finish the same work in 2 days. 15 men and 20 women can do the same work in - days.
Options: a. 4 days, b. 6 days, c. 2 days, d. 8 days, e. 10 days

Ex Output:
a


Ex Input:
Problem: mary works in a restaurant a maximum of 70 hours. for the first 20 hours, she is paid $ 8 per hour. for each overtime hour, she is paid at a rate which is 25 % higher than her regular rate. how much mary can earn in a week ?
Options: a. 600, b. 620, c. 660, d. 320, e. 400

Ex Output:
c


Ex Input:
Problem: what is the probability of rolling a total of 5 with a single roll of two fair 6 - sided dice, each with the distinct numbers 1 through 6 on each side ?
Options: a. 1 / 12, b. 1 / 6, c. 2 / 7, d. 1 / 3, e. 1 / 9

Ex Output:

e