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: 12. what is the dividend. divisor 17, the quotient is 9 and the remainder is 10.
Options: a. 150, b. 152, c. 154, d. 163, e. 144

Ex Output:
d

Ex Input:
Problem: how many prime numbers are between 76 / 8 and 124 / 5 ?
Options: a. 1, b. 2, c. 3, d. 4, e. 5

Ex Output:
e

Ex Input:
Problem: 24 lbs of coffee p and 25 lbs of coffee v are mixed to make coffee x and y. the ratio of p to v in coffee x is 4 to 1, in y is 1 to 5. how much of p is contained in the mixture x ?
Options: a. 10, b. 20, c. 30, d. 40, e. 50

Ex Output:
b