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: calculate the share of z, if rs. 3720 is divided among x, y and z in the ratio 7: 8: 11 ?
Options: a. 1564.1, b. 1214.1, c. 1574.1, d. 1271.1, e. 1044.1

Ex Output:
c


Ex Input:
Problem: kathleen can paint a room in 4 hours, and anthony can paint an identical room in 5 hours. how many hours would it take kathleen and anthony to paint both rooms if they work together at their respective rates ?
Options: a. 8 / 15, b. 40 / 9, c. 15 / 8, d. 9 / 4, e. 15 / 4

Ex Output:
b


Ex Input:
Problem: a man buys a cycle for rs. 2800 and sells it at a loss of 25 %. what is the selling price of the cycle ?
Options: a. s. 2090, b. s. 2160, c. s. 2100, d. s. 2202, e. s. 2092

Ex Output:

c