Drug samples:

A) may be sold to any qualified person
B) traded between people for other drugs that they may require
C) may not be sold unless to another physician
D) may not be sold

D) may not be sold
Drug samples may not be sold. They are provided by drug companies so physicians can give them out free of charge as samples; this is to promote future sales of these drugs. Trading drugs between different people is not a legal activity. The patient who is intended to take a drug–whether it is a free sample or a prescribed, purchased drug–is the only one who should take it.