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 range q of the 6 numbers 4, 314, 710 and x is 12, what is the difference between the greatest possible value of x and least possible value of x ?
Options: a. 0, b. 2, c. 12, d. 13, e. 15
Example Output: d

Example Input: Problem: what is the rate percent when the simple interest on rs. 720 amount to rs. 180 in 4 years ?
Options: a. 6.25, b. 7.25, c. 8.25, d. 9.25, e. 10.25
Example Output: a

Example Input: Problem: when n is divided by 5 the remainder is 3. what is the remainder when ( n + 3 ) ^ 2 is divided by 5 ?
Options: a. 0, b. 1, c. 2, d. 3, e. 4
Example Output:
b