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: the present population of a town is 2000. population increase rate is 20 % p. a. find the population of town after 1 years ?
Options: a. 1000, b. 2400, c. 1500, d. 1600, e. 1250

Ex Output:
b


Ex Input:
Problem: what is the normal price of an article sold at $ 72 after two successive discounts of 10 % and 20 % ?
Options: a. $ 92, b. $ 96, c. $ 100, d. $ 104, e. $ 108

Ex Output:
c


Ex Input:
Problem: in a kilometer race, a beats b by 48 meters or 12 seconds. what time does a take to complete the race ?
Options: a. 238 sec, b. 190 sec, c. 667 sec, d. 167 sec, e. 176 sec

Ex Output:

a