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 12 machine can finish a job in 40 days, then how many more machines would be needed to finish the job in one - fourth less time ?
Options: a. a. 4, b. b. 8, c. c. 10, d. d. 12, e. e. 16
Example Output: a

Example Input: Problem: of 30 applicants for a job, 9 had at least 4 years ' experience, 18 had degrees, and 3 had less than 4 years ' experience and did not have a degree. how many of the applicants had at least 4 years ' experience and a degree ?
Options: a. 14, b. 10, c. 9, d. 7, e. 5
Example Output: b

Example Input: Problem: the price of an item is discounted 10 percent on day 1 of a sale. on day 2, the item is discounted another 10 percent, and on day 3, it is discounted an additional 30 percent. the price of the item on day 3 is what percentage of the sale price on day 1 ?
Options: a. 28 %, b. 63 %, c. 64.8 %, d. 70 %, e. 72 %
Example Output:
b