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: when 242 is divided by a certain divisor the remainder obtained is 15. when 698 is divided by the same divisor the remainder obtained is 27. however, when the sum of the two numbers 242 and 698 is divided by the divisor, the remainder obtained is 5. what is the value of the divisor ?
Options: a. 11, b. 17, c. 13, d. 23, e. 37

Ex Output:
e

Ex Input:
Problem: 3 candidates in an election and received 6136, 7636 and 11628 votes respectively. what % of the total votes did the winning candidate got in that election ?
Options: a. 46 %, b. 49 %, c. 57 %, d. 59 %, e. 61 %

Ex Output:
a

Ex Input:
Problem: a cyclist bikes x distance at 10 miles per hour and returns over the same path at 9 miles per hour. what is the cyclist ' s average rate for the round trip in miles per hour ?
Options: a. 8.1, b. 8.3, c. 8.6, d. 8.9, e. 9.5

Ex Output:
e