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.

Example Input: Problem: a store reported total sales of $ 460 million for february of this year. if the total sales for the same month last year was $ 320 million, approximately what was the percent increase in sales ?
Options: a. 2 %, b. 17 %, c. 44 %, d. 65 %, e. 83 %
Example Output: c

Example 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
Example Output: e

Example Input: Problem: how many multiples of 4 are there between 12 and 104, inclusive ?
Options: a. 21, b. 22, c. 23, d. 24, e. 25
Example Output:
d