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: the total age of a and b is 12 year more than the total age of b and c. c is how many years younger than a ?
Options: a. 12, b. 24, c. data inadequate, d. none of these, e. 34

Ex Output:
a


Ex Input:
Problem: you have been given a physical balance and 7 weights of 40, 42, 36, 33, 47, 52 and 67 kgs. keeping weights on one pan and object on the other, what is the maximum you can weigh less than 169 kgs.
Options: a. 163, b. 166, c. 162, d. 164, e. 165

Ex Output:
e


Ex Input:
Problem: the average ( arithmetic mean ) of 4 different integers is 76. if the largest integer is 90, what is the least possible value of the smallest integer ?
Options: a. 1, b. 19, c. 29, d. 30, e. 37

Ex Output:

e