In psychopharmacology, the term efficacy means:

A. Efficacy refers to the maximal therapeutic effect that a drug can achieve, regardless of the dose. In psychopharmacology, this indicates how well a medication can alleviate symptoms when used appropriately. B. The amount of drug needed to achieve its maximum effect refers to potency, not efficacy. Potency is about the dose required, while efficacy is about the maximum possible benefit. C. The time it takes for half the drug to be removed from the bloodstream is the half-life, a pharmacokinetic property, not efficacy. D. The dosage of the medication simply describes the prescribed amount and schedule of administration. It does not define efficacy.