Instructions: 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: Problem: in a circuit board factory, all circuit boards that pass a verification process are certified. every board that fails the verification process is indeed faulty, but 1 / 8 of those that pass are also faulty. approximately how many faulty circuit boards exist in a group of 3,200 circuit boards where 64 fail inspection ?
Options: a. 72, b. 192, c. 456, d. 256, e. 264
Output:
c