In the Classroom Experiment Where a Mug Is Bought and Sold

In the classroom experiment where a mug is bought and sold,

A) acquiring the mug was perceived to be a greater "gain" for those who acquired it than the "loss" for those who gave it up.
B) giving up the mug was perceived to be a greater "loss" to those who had one than the "gain" from obtaining a mug for those without one.
C) the price at which the mug was exchanged compensated precisely the value gained and lost by the traders.
D) the price at which the mug could be sold was always less than the price at which the mug was acquired.