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: a library branch originally contained 18360 volumes, 30 % of which were fiction novels. 1 / 3 of the volumes were transferred to another location and 1 / 5 of the volumes transferred were fiction novels. what percent of the remaining collection was fiction novels ?
Options: a. 2.5 %, b. 17.67 %, c. 28.3 %, d. 36 %, e. 73.6 %

Ex Output:
d


Ex Input:
Problem: how much is 60 % of 40 is greater than 4 / 5 of 30 ?
Options: a. 8, b. 3, c. 7, d. 0, e. 1

Ex Output:
d


Ex Input:
Problem: peter invested a certain sum of money in a simple interest bond whose value grew to $ 300 at the end of 3 years and to $ 400 at the end of another 5 years. what was the rate of interest in which he invested his sum ?
Options: a. 12 %, b. 12.5 %, c. 6.67 %, d. 6.25 %, e. 8.33 %

Ex Output:

e