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: mrs. evans gave a test to her freshmen economics class, which has 29 students enrolled and 19 of them answered question 1 correctly. if 24 answered question 2 correctly and 5 did not take the test then how many answered both questions correctly ?
Options: a. 3, b. 9, c. 11, d. 17, e. 19
Example Output: e

Example Input: Problem: the speed of the boat in still water in 12 kmph. it can travel downstream through 54 kms in 3 hrs. in what time would it cover the same distance upstream ?
Options: a. 8 hours, b. 6 hours, c. 4 hours, d. 5 hours, e. 9 hours
Example Output: e

Example Input: Problem: the salary of a person was reduced by 28 %. by what percent should his reduced salary be raised so as to bring it at par with his original salary ?
Options: a. 10 %, b. 15 %, c. 20 %, d. 25 %, e. 38.9 %
Example Output:
e