Evidence That Contradicts Zajonc's Mere Presence Theory of Social Facilitation

Evidence that contradicts Zajonc's mere presence theory of social facilitation is that when observers are blindfolded,their presence

A) does not boost performance on a simple task.
B) hinders performance on a complex task.
C) boosts performance on a simple task.
D) is a distraction that leads to poorer performance on both simple and complex tasks.