Melissa Has Been Assigned to Do a Group Project with Three

Melissa has been assigned to do a group project with three other students. She knows that two of them are good students who will do an excellent job on the project. Since the teacher won't know who has done what work on the project, she doesn't bother to work very hard. The smart kids, as she thinks of them, can do the work. Her apparent laziness is due to

A) social facilitation.
B) groupthink.
C) the norm of reciprocity.
D) social loafing.