Which of the following is NOT one of the four basic techniques used in physical assessment?

The correct choice indicates that olfaction is not classified among the four fundamental techniques of physical assessment. The four traditional techniques employed during a physical assessment are inspection, palpation, percussion, and auscultation.

Inspection involves a careful visual examination of the patient, assessing various physical attributes such as skin condition, color, and overall appearance. Palpation involves using the hands to feel for abnormalities, tenderness, or swelling in different parts of the body. Percussion is the technique of tapping on the body's surface to produce sounds, thereby gaining information about the underlying organs. Finally, auscultation is the skill of listening to internal body sounds, typically with a stethoscope, to evaluate heart, lung, and digestive function.

While olfaction, which involves the sense of smell, can indeed provide valuable observations in some clinical scenarios—such as detecting certain odors that may indicate specific conditions—it is not officially categorized as one of the core techniques in standard physical assessment, and thus, is the answer to the question.