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.

Input: Consider 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

Output: b

Input: Consider Input: Problem: of all the homes on gotham street, 1 / 3 are termite - ridden, and 4 / 7 of these are collapsing. what fraction of the homes are termite - ridden, but not collapsing ?
Options: a. 1 / 3, b. 1 / 4, c. 1 / 5, d. 1 / 6, e. 1 / 7

Output: e

Input: Consider Input: Problem: a cycle is bought for rs. 900 and sold for rs. 1170, find the gain percent ?
Options: a. 27 %, b. 20 %, c. 80 %, d. 30 %, e. 24 %
Output: d