In the Classroom Mug Experiment, Students Receive the Mug for Free

In the classroom mug experiment, students receive the mug for free and are willing to sell it:

A) for less than it's perceived market value, since it was free in the first place.
B) for exactly the perceived market value, without enjoying a gain or suffering a loss.
C) only for more than its perceived market value; otherwise it would create a perceived loss.
D) for any amount the buyer would offer, since it was free in the first place.