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.

Input: Consider Input: Problem: what is the perimeter of a square field whose diagonal is 8 a s 2 ?
Options: a. 64 m, b. 32 m, c. 30 m, d. 16 m, e. 18 m

Output: b

Input: Consider Input: Problem: what is the smallest integer that is multiple of 5, 711
Options: a. a. 70, b. b. 35, c. c. 385, d. d. 280, e. e. 140

Output: c

Input: Consider Input: Problem: the current in a river is 10 mph. a boat can travel 50 mph in still water. how far up the river can the boat travel if the round trip is to take 5 hours ?
Options: a. 120, b. 100, c. 96, d. 85, e. 150
Output: a