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: ravi purchased a refrigerator and a mobile phone for rs. 15000 and rs. 8000 respectively. he sold the refrigerator at a loss of 5 percent and the mobile phone at a profit of 10 percent. overall he make a.
Options: a. 50, b. 288, c. 27, d. 200, e. 881

Ex Output:
a


Ex Input:
Problem: of all the homes on gotham street, 1 / 3 are termite - ridden, and 4 / 7 of these are collapsing. what fraction of the homes are termite - ridden, but not collapsing ?
Options: a. 1 / 3, b. 1 / 4, c. 1 / 5, d. 1 / 6, e. 1 / 7

Ex Output:
e


Ex Input:
Problem: a ( 3, w ^ 3 ) is the ( x, y ) coordinate of point located on the parabola y = x ^ 2 - 1. what is the value of w ?
Options: a. 2., b. 4., c. 5., d. 6., e. 9.

Ex Output:

a