Answer:
A cafeteria because all of the other choices would be biased towards the sport/activity that is already occurring.
Explanation:
During a wrestling match, people are definitely going to be directed towards wrestling. During a basketball game, people prefer basketball. During a chorus or choir, people prefer choir most likely.
When in a cafeteria, people just sit there and eat or play games or talk.
People are also stationary so people won't be yelling at you to back off when you jump in the stadium for wrestling/basketball and start blasting questions at someone in a headlock.