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 rectangular tiled patio is composed of 96 square tiles. the rectangular patio will be rearranged so that there will be 2 fewer columns of tiles and 4 more rows of tiles. after the change in layout, the patio will still have 96 tiles, and it will still be rectangular. how many rows are in the tile patio before the change in layout ?
Options: a. 5, b. 6, c. 8, d. 13, e. 28
Example Output: c

Example Input: Problem: a student travels from his house to school at 12 km / hr and reaches school 2 hours late. the next day he travels 20 km / hr and reaches school 1 hour early. what is the distance between his house and the school ?
Options: a. 90, b. 100, c. 110, d. 120, e. 130
Example Output: a

Example Input: Problem: a fort had provision of food for 150 men for 45 days. after 10 days, 25 men left the fort. find out the number of days for which the remaining food will last.
Options: a. 44, b. 42, c. 40, d. 38, e. 36
Example Output:
b