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 total age of a and b is 15 years more than the total age of b and c. c is how many year younger than
Options: a. 14 years, b. 12 years, c. 56 years, d. 66 years, e. 15 years
Example Output: e

Example Input: Problem: what will be the compound interest on a sum of rs. 20,000 after 3 years at the rate of 12 % p. a. ?
Options: a. rs. 8098.56, b. rs. 9720, c. rs. 10123.20, d. rs. 10483.20, e. none
Example Output: a

Example Input: Problem: in the youth summer village there are 175 people, 100 of them are not working, 75 of them have families and 125 of them like to sing in the shower. what is the largest possible number of people in the village, which are working, that do n ' t have families and that are singing in the shower ?
Options: a. 70, b. 75, c. 85, d. 80, e. 100
Example Output:
b