Although Many Substances Can Be Considered to Be a Drug

Although many substances can be considered to be a drug, a drug is considered to be:

A) Any substance that is taken to prevent, cure, or reduce symptoms of a medical condition.
B) Any substance that is found in nature, or that normally occurs in the body.
C) Any substance that is synthesized and tested in the laboratory setting.
D) Any substance that can be isolated from natural substances in nature.