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.

Ex Input:
Problem: if x + y = 260, x - y = 200, for integers of x and y, y = ?
Options: a. 200, b. 230, c. 50, d. 115, e. 150

Ex Output:
b


Ex Input:
Problem: mr. loyd wants to fence his square shaped land of 120 sqft each side. if a pole is laid every 12 ft how many poles do he need ?
Options: a. 20, b. 30, c. 40, d. 50, e. 60

Ex Output:
c


Ex Input:
Problem: indu gave bindu rs. 1875 on compound interest for 2 years at 4 % per annum. how much loss would indu has suffered had she given it to bindu for 2 years at 4 % per annum simple interest ?
Options: a. s. 10, b. s. 2, c. s. 5, d. s. 3, e. s. 4

Ex Output:

d