Answer: D. auscultation.
Explanation: In auscultation, the healthcare professional can listen to sounds that are produced in the body. For example, he or she may use a stethoscope to listen to the lungs and hear the patient’s breath sounds. Patients without any disease process occurring in the lungs should have clear breath sounds. In a patient who has an infection or has fluid in the lungs, the healthcare professional hears crackles and noises within the lungs. Some sounds, like cracking joints, can be heard without a stethoscope... PF