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.

Input: Consider Input: Problem: if each participant of a chess tournament plays exactly one game with each of the remaining participants, then 276 games will be played during the tournament. find the number of participants.
Options: a. 20, b. 22, c. 24, d. 26, e. 28

Output: c


Input: Consider Input: Problem: if x and y are positive integers and 3 + x + y + xy = 17, what is the value of x + y ?
Options: a. 3, b. 5, c. 6, d. 8, e. 9

Output: c


Input: Consider Input: Problem: what is the area of a square field whose sides have a length of 11 meters ?
Options: a. 225 sq m, b. 205 sq m, c. 121 sq m, d. 167 sq m, e. 156 sq m


Output: c