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: what is the tens digit of 6 ^ 10 ?
Options: a. 7, b. 3, c. 5, d. 1, e. 9

Ex Output:
a


Ex Input:
Problem: ramesh purchased a refrigerator for rs. 12500 after getting a discount of 20 % on the labelled price. he spent rs. 125 on transport and rs. 250 on installation. at what price should it be sold so that the profit earned would be 18 % if no discount was offered ?
Options: a. 17608, b. 17606, c. 17604, d. 17600, e. 18880

Ex Output:
e


Ex Input:
Problem: the length of a rectangle is increased by 15 % and its breadth is decreased by 20 %. what is the effect on its area ?
Options: a. 1288, b. 1299, c. 1000, d. 10000, e. 9200

Ex Output:

e