Correct Answer:
Option D - A stethoscope does not have an optical lens. A stethoscope can be used to listen to the sounds made by the heart, lungs or intestines as well as blood flow in arteries and viens.
D. A stethoscope does not have an optical lens. A stethoscope can be used to listen to the sounds made by the heart, lungs or intestines as well as blood flow in arteries and viens.