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: if the simple interest on a certain sum of money for 6 years is one – fifth of the sum, then the rate of interest per annum is
Options: a. 3.3 %, b. 7.2 %, c. 6.1 %, d. 5.0 %, e. 3.1 %

Output: a


Input: Consider Input: Problem: what is the units digit of ( 3 ^ 13 ) ( 4 ^ 13 ) ?
Options: a. 2, b. 4, c. 6, d. 7, e. 8

Output: a


Input: Consider Input: Problem: jack and jill work at a hospital with 7 other workers. for an internal review, 2 of the 9 workers will be randomly chosen to be interviewed. what is the probability that jack and jill will both be chosen ?
Options: a. 1 / 3, b. 1 / 4, c. 1 / 15, d. 3 / 8, e. 1 / 36


Output: e