What does the term "Catheter" refer to in medical practices?

The term "Catheter" refers specifically to a device designed for draining fluids from the body or allowing fluids to be introduced into the body. This can include urinary catheters, which are used to drain urine from the bladder, as well as intravenous catheters, which are inserted into a vein to administer medications or fluids. The primary function of a catheter is to facilitate the movement of fluids, making option A the correct answer.

Other choices do not accurately capture the primary function of a catheter. For instance, a measurement device typically involves tools used to assess or quantify various parameters, while a type of medication refers to substances used to treat illnesses or conditions. A surgical instrument encompasses tools used specifically during surgical procedures, but they do not serve the same function as catheters in terms of fluid management. The specificity of a catheter's role in fluid drainage distinguishes it from these other medical items.