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: a shopkeeper sold 30 articles at the cost price of 35 articles. then find the profit % or lost %
Options: a. 12 %, b. 15 %, c. 16.67 %, d. 18 %, e. 22 %

Output: c

Input: Consider Input: Problem: lucy bought a 1 - year, 10000 certificate of deposit that paid interest at an annual rate of 8 percent compunded semiannually. what was the total amount of interest paid on this certificate at maturity ?
Options: a. 10464, b. 864, c. 816, d. 800, e. 480

Output: d

Input: Consider Input: Problem: the radius of a wheel is 20.4 cm. what is the distance covered by the wheel in making 400 resolutions ?
Options: a. 512.448 m, b. 704 m, c. 510.448 m, d. 706 m, e. 204 m
Output: a