Final answer:
The PDR is a compilation of package inserts that provides comprehensive drug prescribing information for healthcare professionals. It is the Physician's Desk Reference and contains FDA-approved labeling information on medications.
Step-by-step explanation:
The PDR stands for Physician's Desk Reference, which is a reference book that is A) a compilation of package inserts. It includes FDA-approved labeling information and is widely used by healthcare professionals to find information about medications such as dosage, side effects, interactions, and indications. The PDR, therefore, serves as a comprehensive resource for drug prescribing information.
While the PDR does provide information on medications, it is not B) a reference that defines the standards for medications; standards for medications and their approval are set by regulatory agencies like the FDA. Moreover, the PDR is not specifically focused on C) parenteral medications or D) dietary supplements, though such products may also be found within its pages if they are FDA approved.