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 hiker walked for 3 days. she walked 18 miles on the first day, walking 3 miles per hour. on the second day she walked for one less hour but she walked one mile per hour, faster than on the first day. on the third day 5 miles per hour for 6 hours. how many miles in total did she walk ?
Options: a. 68, b. 44, c. 58, d. 60, e. 62

Ex Output:
a


Ex Input:
Problem: a train traveled the first d miles of its journey it an average speed of 50 miles per hour, the next d miles of its journey at an average speed of y miles per hour, and the final d miles of its journey at an average speed of 160 miles per hour. if the train ’ s average speed over the total distance was 96 miles per hour, what is the value of y ?
Options: a. 68, b. 84, c. 90, d. 120, e. 160

Ex Output:
e


Ex Input:
Problem: a distributor sells a product through an online store, which take a commission of 20 % of the price set by the distributor. the distributor obtains the product from a producer at the price of $ 18 per item. what is the price that the buyer observers online if the distributor wants to maintain a 20 % profit on the cost of the item ?
Options: a. $ 25, b. $ 26, c. $ 27, d. $ 28, e. $ 29

Ex Output:

c