Which of the following can cause hypotension?

Medication effects can indeed cause hypotension, which is characterized by abnormally low blood pressure. Certain medications, such as those used to treat hypertension, diuretics, and some antidepressants, can lead to a decrease in blood pressure as a side effect. This is due to their pharmacological action, which may lower vascular resistance or decrease blood volume, either of which can result in lower blood pressure readings.

Overhydration can lead to hypertension rather than hypotension, as excessive fluid can increase blood volume. Excessive exercise might temporarily lower blood pressure, but generally, regular exercise helps to maintain or elevate blood pressure in a healthy range. High protein intake does not typically cause hypotension; in fact, adequate protein intake is essential for maintaining overall health and bodily functions, including cardiovascular health. Thus, medication effects are the primary factor among the options provided that can lead to hypotension.