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.

Example 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
Example Output: d

Example Input: Problem: what is the total number of integers between 10 and 50 that are divisible by 2 ?
Options: a. 18, b. 19, c. 22, d. 25, e. 10
Example Output: b

Example Input: Problem: the greatest number that divides 690 and 875 leaving remainders 10 and 25 respectively is :
Options: a. 170, b. 130, c. 150, d. 120, e. 180
Example Output:
a