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 group of hikers is planning a trip that will take them up a mountain using one route and back down using another route. they plan to travel down the mountain at a rate of one and a half times the rate they will use on the way up, but the time each route will take is the same. if they will go up the mountain at a rate of 7 miles per day and it will take them two days, how many miles long is the route down the mountain ?
Options: a. 18, b. 19, c. 20, d. 21, e. 22

Ex Output:
d


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: what percent is 320 gm of 1 kg ?
Options: a. 25 %, b. 40 %, c. 10 %, d. 8 %, e. 32 %

Ex Output:

e