“PDR” is the acronym for which of the following?

• A. Physiologically dependent reaction
• B. Peterson's Descriptive Reference
• C. Phenolic disinfectant reaction
• D. Physician's Desk Reference

Answer: (D)

PDR refers to a well-known reference that clinicians rely on to look up medications, including their indications, dosages, interactions, and safety information. This makes it the best answer because the Physician's Desk Reference is a standard, recognized resource in medical and veterinary contexts, aligning with how the acronym PDR is commonly used in labs and clinics. The other options don’t correspond to established reference works: physiologically dependent reaction isn’t a standard reference, Peterson's Descriptive Reference isn’t a recognized resource, and phenolic disinfectant reaction describes a chemical process rather than a reference book.