Which statement is most accurate about group behavior? a. people tend to perform well-practiced skills better in front of an audience. b. social loafing is a form of bystander apathy. c. nervousness tends to impair performance in front of an audience. d. cheering fans at a sports event produce evaluation apprehension in the players.

I believe the correct answer is D. Cheering fans at a sports event produce evaluation apprehension in the players.
If fans cheer for players, then players feel they cannot fail their fans. This is why they may get nervous because they are constantly thinking about how they have to be good so as not to disappoint the team or the fans.
A is not necessarily correct because you may practice as much as you can and still do poorly in front of an audience. B is incorrect because it's too harsh to call it bystander apathy. C is incorrect because sometimes you can do even better because of your nervousness.