When Differentiating Between Free Drug Molecules and Drug Molecules That

When differentiating between free drug molecules and drug molecules that have bound to plasma proteins,the main focus is:

A) Only unbound or free drug molecules can exert a pharmacological effect.
B) Only drug molecules that have bound to plasma can exert a pharmacological effect.
C) Free drug molecules exert the same level of pharmacological effect as drug molecules that are bound to plasma.
D) None of these are correct