Final answer:
A catheter is a medical tube for draining or injecting fluids into the body, while a stethoscope is used for listening to internal sounds, a speculum for examining orifices, and a cannula for vein access.
Step-by-step explanation:
The correct answer to the question is b) Catheter. A catheter is a rubber or plastic tube used medically to drain fluids from or inject fluids into a body cavity or vessel. It can be inserted into various body openings or into the bloodstream to treat diseases or perform a surgical procedure. On the other hand, a stethoscope is an acoustic device used for auscultating or listening to sounds from the heart, lungs, and other organs, typically during a physical examination.
A speculum is a device inserted into an orifice to dilate it for examination purposes, whereas a cannula is a thin tube inserted into a vein or body cavity to administer medication, drain off fluid, or insert a surgical instrument. Catheters are widely used in medical procedures and are critical for treatments that require access to the body's internal systems.