Final answer:
Blood flow can be determined by pressure.
Step-by-step explanation:
The height to which blood can be pumped is primarily determined by pressure.
Pressure is the force exerted by the blood against the walls of the blood vessels. It is responsible for pushing the blood through the circulatory system.
For example, when the heart contracts during systole, it generates pressure that propels the blood forward. This pressure allows the blood to be pumped to different parts of the body, reaching even the tallest heights.