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: an investor deposited $ 10,000 to open a new savings account that earned 12 percent annual interest, compounded quarterly. if there were no other transactions in the account, what was the amount of money in the account 6 months after the account was opened ?
Options: a. $ 10,300, b. $ 10,303, c. $ 10,600, d. $ 10,609, e. $ 10,900

Ex Output:
d


Ex Input:
Problem: a / ( b / c. in the expression above, a, b, and c are different numbers and each is one of the numbers 2, 3, or 6. what is the largest possible value of the expression ?
Options: a. 2 / 18, b. 6 / 3, c. 30 / 2, d. 18 / 2, e. 6 / 18

Ex Output:
d


Ex Input:
Problem: the average age of students of a class is 15.8 years. the average age of boys in the class is 16.5 years and that of the girls is 15.4 years. the ration of the number of boys to the number of girls in the class is :
Options: a. 2: 5, b. 2: 3, c. 2: 4, d. 2: 1, e. 4: 7

Ex Output:

e