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: sheila works 8 hours per day on monday, wednesday and friday, and 6 hours per day on tuesday and thursday. she does not work on saturday and sunday. she earns $ 360 per week. how much does she earn in dollars per hour ?
Options: a. 11, b. 10, c. 9, d. 8, e. 7

Ex Output:
b


Ex Input:
Problem: four bells commence tolling together and toll at intervals of 2, 4, 6, 8 seconds respectively. in 18 minutes, how many times do they toll together ?
Options: a. 43, b. 44, c. 45, d. 46, e. 47

Ex Output:
c


Ex Input:
Problem: in triangle pqr, the angle q = 90 degree, pq = 4 cm, qr = 8 cm. x is a variable point on pq. the line through x parallel to qr, intersects pr at y and the line through y, parallel to pq, intersects qr at z. find the least possible length of xz
Options: a. 1.2 cm, b. 2.4 cm, c. 4.8 cm, d. 2.16 cm, e. 3.2 cm

Ex Output:

e