What Distinguishes Reversible Inhibitors from Irreversible Inhibitors

Multiple Choice

What distinguishes reversible inhibitors from irreversible inhibitors?

A) Reversible inhibitors are not covalently bound to enzymes but irreversible inhibitors are.
B) There is an equilibrium between bound and unbound reversible inhibitor.There usually is little back reaction for the binding of an irreversible inhibitor.
C) Reversible inhibitors can often be retrieved (purified) from solutions of enzymes,but irreversible inhibitors will react with enzyme and no longer be retrievable in their original form.
D) All of the above.
E) A and B only.