The correct answer is D. Pharmacokinetics is the study of how the body acts on a medicine, including how it gets into the body, to the active site, and out of the body.

The correct answer is B. Pharmacodynamics is the study of how a medicine acts in the body—both at its intended target and throughout all the organs and tissues in the body.

The correct answer is C. Pharmacogenetics is the study of how a single gene affects the body’s response to medicine. (The related branch of pharmacogenomics is the study of how an entire genome affects that response.)

The correct answer is B. The term ADME includes absorption, distribution, metabolism, and excretion. Enzymes often metabolize medicines, breaking them down into metabolites that are more easily excreted from the body.

The correct answer is D. Antagonists bind to receptors and block other molecules from activating them. Molecules that activate receptors, even partially, are called agonists.