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: if the wages of 6 men for 15 days be rs. 2100, then find the wages of for 12 days.
Options: a. rs. 2420, b. rs. 2500, c. rs. 2520, d. rs. 2020, e. rs. 2650
Example Output: c

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: a 10 % stock yields 8 %. the market value of the stock is :
Options: a. rs. 72, b. rs. 125, c. rs. 112.50, d. rs. 116.50, e. none of these
Example Output:
b