Final answer:
The best physical status modifier for a normal, healthy patient undergoing anesthesia is P1, as it indicates no systemic disease and no functional limitations.
Step-by-step explanation:
The physical status modifier that best describes a normal, healthy patient who is undergoing anesthesia is P1. This classification is used by anesthesiologists to assess a patient's preoperative health status according to the American Society of Anesthesiologists (ASA) Physical Status Classification System. The P1 classification indicates a patient without systemic disease and with no substantive functional limitations, making it the appropriate choice for a normal, healthy patient. The surgeon, nurse, and anesthesia professional often review the patient's ASA status as part of discussing key concerns for the patient's recovery and care.