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: 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 %
Example Output: d

Example Input: Problem: out of 40 applicants to a law school, 15 majored in political science, 20 had a grade point average higher than 3.0, and 10 did not major in political science and had a gpa equal to or lower than 3.0. how many e applicants majored in political science and had a gpa higher than 3.0 ?
Options: a. 5, b. 10, c. 15, d. 25, e. 35
Example Output: a

Example Input: Problem: simple interest on a certain sum at a certain annual rate of interest is 1 / 9 of the sum. if the numbers representing rate percent and time in years be equal, then the rate of interest is :
Options: a. 5, b. 8, c. 3 1 / 3, d. 2 2 / 3, e. none of these
Example Output:
c