Final answer:
Option (b), A catheter is a thin rubber tube that uses capillary action to facilitate drainage or the drawing up of fluids such as blood. This phenomenon relies on the adhesive forces between the liquid and the tube's surface.
Step-by-step explanation:
The thin rubber tube that facilitates drainage by capillary action is referred to as a catheter. Capillary action is a phenomenon where the adherence of the liquid to the walls of a narrow tube, such as a catheter, can cause the liquid to rise within the tube. This principle is applied in various medical procedures, including the collection of blood for medical analysis. Adhesive forces between the molecules in the blood and those at the glass surface of a capillary tube can draw the blood up against gravity.
For example, during a glucose test for a diabetic patient or determining hematocrit levels in athletes, capillary action allows blood to be drawn into a small-diameter glass tube. The distance the liquid travels is determined by the size of the tube; the smaller the diameter, the greater the relative surface area and, consequently, the stronger the adhesive forces that can pull the fluid upwards.