Which of the following is a sign of a hypotensive reaction?

A hypotensive reaction refers to a significant drop in blood pressure, which can lead to a variety of symptoms. Sweating, nausea, and dizziness are all commonly associated with a hypotensive reaction as they are the body's responses to decreased blood flow and oxygen to the brain and other vital organs.

Sweating can occur as the body attempts to compensate for the sudden drop in blood pressure, activating the sympathetic nervous system. Nausea may arise as the body reacts to the discomfort and instability caused by the change in blood pressure. Dizziness is often reported due to reduced perfusion to the brain, making it difficult to maintain balance and orientation.

Since each of these symptoms can manifest during a hypotensive reaction, the answer that encompasses all these signs together is indeed the most comprehensive and accurate. It's essential for individuals, especially in medical or plasma donation settings, to recognize these symptoms as indicators of a possible hypotensive reaction requiring attention.