Which of the following medications is known as an anti-hypertensive?

The classification of a calcium channel blocker as an anti-hypertensive medication is accurate because its primary function is to lower blood pressure by relaxing blood vessels. Calcium channel blockers work by inhibiting the influx of calcium ions into the cardiovascular system's smooth muscle and cardiac muscle. This action causes relaxation of the blood vessels, lowering peripheral vascular resistance, and ultimately reduces blood pressure levels.

On the other hand, antidepressants are primarily used to treat mood disorders and do not have a direct role in managing hypertension. Anticonvulsants are medications that help control seizures and have different therapeutic uses, generally unrelated to blood pressure management. Alzheimer's medications are designed to address symptoms related to cognitive decline and do not function to lower blood pressure. Therefore, among the options provided, a calcium channel blocker is the only medication identified specifically for its role in treating hypertension.