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: arjun started a business with rs. 20,000 and is joined afterwards by anoop with rs. 30, 000. after how many months did anoop join if the profits at the end of the year are divided equally ?
Options: a. 3, b. 4, c. 5, d. 6, e. 7

Ex Output:
b


Ex Input:
Problem: kim has 3 pairs of shoes; each pair is a different color. if kim randomly selects 2 shoes without replacement from the 6 shoes, what is the probability that she will select 2 shoes of the same color ?
Options: a. 2 / 5, b. 1 / 5, c. 1 / 9, d. 1 / 10, e. 1 / 25

Ex Output:
b


Ex Input:
Problem: the shopkeeper increased the price of a product by 25 % so that customer finds it difficult to purchase the required amount. but somehow the customer managed to purchase only 76 % of the required amount. what is the net difference in the expenditure on that product ?
Options: a. 12.5 %, b. 13 %, c. 5 %, d. 17 %, e. 19 %

Ex Output:

c