What do antihypertensive drugs do?

Antihypertensive drugs are specifically designed to lower blood pressure, making the correct answer accurate. These medications work through various mechanisms, such as relaxing blood vessels, reducing heart rate, or decreasing blood volume, which collectively help to decrease the strain on the cardiovascular system. By effectively managing hypertension, these drugs can help reduce the risk of heart attack, stroke, and other serious health issues associated with high blood pressure.

The other options describe effects that do not accurately reflect the primary purpose of antihypertensive medications. Some medications may indeed help improve circulation or influence factors related to blood clots, but that is not the primary function of antihypertensives. Their focus is entirely on lowering blood pressure, thereby safeguarding long-term cardiovascular health.