Which Statement Regarding Drug-Receptor Behavior Is Correct

Multiple Choice

Which statement regarding drug-receptor behavior is correct?

A) The intensity of response is proportional to the number of receptors occupied.
B) A drug's intensity and duration of effect are irreversible because forces holding the drug to its receptor are strong.
C) All receptors for drugs are located externally on the cell membrane.
D) All drugs are selective in that they bind to one type of receptor and produce very predictable and specific effects.