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: at 15: 00 there were 22 students in the computer lab. at 15: 03 and every three minutes after that, 3 students entered the lab. if at 15: 10 and every ten minutes after that 8 students left the lab, how many students were in the computer lab at 15: 44 ?
Options: a. 7, b. 14, c. 25, d. 27, e. 32
Example Output: e

Example Input: Problem: by selling 20 pencils for a rupee a man loses 30 %. how many for a rupee should he sell in order to gain 30 % ?
Options: a. 8.56, b. 10.75, c. 14.5, d. 16.5, e. 11.4
Example Output: b

Example Input: Problem: a store sells chairs and tables. if the price of 2 chairs and 1 table is 60 % of the price of 1 chair and 2 tables, and the price of 1 table and 1 chair is $ 72, what is the price, in dollars, of 1 table ? ( assume that every chair has the same price and every table has the same price. )
Options: a. 55, b. 84, c. 63, d. 75, e. 70
Example Output:
c