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: if 7 a = 8 b and ab ≠ 0, what is the ratio of a / 8 to b / 7 ?
Options: a. 16 / 14, b. 8 / 7, c. 1, d. 7 / 8, e. 64 / 49

Output: c


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

Output: b


Input: Consider Input: Problem: a pet store holds cats and dogs. if the difference between the number of cats and the number of dogs is 7. what could be the ratio of cats to dogs in the pet store ?
Options: a. 1: 3, b. 1: 4, c. 28: 35, d. 2: 5, e. 4: 6


Output: c