Which of the following best describes pharmacokinetics?

A. This option describes drug-drug interactions, which are part of pharmacodynamics rather than pharmacokinetics. B. The development and manufacturing of drugs pertain more to pharmaceutical sciences than pharmacokinetics. C. Prescribing and administering drugs are related to pharmacotherapy but do not encompass the full scope of pharmacokinetics. D. Pharmacokinetics is defined as the study of how drugs are absorbed, distributed, metabolized, and excreted by the body, providing insights into the drug's action and efficacy.