g If I see a decreased response after administration of repeated doses of a drug I might suspect that the cell has a) Up regulated a receptor b) Blocked receptor action c) Down regulated a receptor d) The drug has acted as an inverse agonist () More than one of the above

More than one of the above

Explanation:

I strongly recommend sticking with the prescribed dosage of a drug.

A drug works by binding itself to the receptor site of a cell or tissue by non-covalent interactions.

Repeated doses of the same drug however may make the drug start behaving as an inverse agonist by blocking (instead of binding) the receptor site of the cell thus inducing a reduced response instead of an increased response to the drug.