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.

Example Input: Problem: the sum of all the integers a such that - 26 < a < 24 is
Options: a. 0, b. - 2, c. - 25, d. - 49, e. - 51
Example Output: d

Example Input: Problem: by selling 20 pencils for a rupee a man loses 30 %. how many for a rupee should he sell in order to gain 30 % ?
Options: a. 8.56, b. 10.75, c. 14.5, d. 16.5, e. 11.4
Example Output: b

Example Input: Problem: the present population of a town is 1240. population increase rate is 4 % p. a. find the population of town after 1 years ?
Options: a. 990, b. 1215, c. 1345, d. 1142, e. 1290
Example Output:
e