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: some persons can do a piece of work in 12 days. two times the number of these people will do half of that work in ?
Options: a. 3, b. 4, c. 5, d. 6, e. 8
Output:
a