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: if the sides of a triangle are 26 cm, 24 cm and 15 cm, what is its area ?
Options: a. 120, b. 772, c. 180, d. 266, e. 2848

Ex Output:
c


Ex Input:
Problem: a and b invests rs. 8000 and rs. 12000 in a business. after 4 months, a withdraws half of his capital and 2 months later, b withdraws one - third of his capital. in what ratio should they share the profits at the end of the year ?
Options: a. 32: 99, b. 82: 31, c. 8: 15, d. 34: 89, e. 35: 21

Ex Output:
c


Ex Input:
Problem: in a 100 m race, sam beats john by 5 seconds. on the contrary, if sam allowed john to start 15 m ahead of sam, then sam and john reach the finishing point at the same time. how long does sam take to run the 100 m race ?
Options: a. 4 seconds, b. 25 seconds, c. 29 seconds, d. 21 seconds, e. 17 seconds

Ex Output:

e