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: the area of one square is x ^ 2 + 4 x + 4 and the area of another square is 4 x ^ 2 − 12 x + 9. if the sum of the perimeters of both squares is 32, what is the value of x ?
Options: a. 0, b. 2, c. 2.5, d. 4.67, e. 3
Example Output: e

Example Input: Problem: what is the compound interest paid on a sum of rs. 3000 for the period of 2 years at 10 % per annum.
Options: a. 630, b. 620, c. 610, d. 600, e. none of these
Example Output: a

Example Input: Problem: a bag of potatoes weighs 50 lbs divided by half of its weight. how much does the bag of potatoes weigh ?
Options: a. 10 lb, b. 20 lb, c. 30 lb, d. 40 lb, e. 50 lb
Example Output:
a