Water Reabsorption in Kidneys During Dehydration

Homeostasis is essential for maintaining the internal environment of living organisms. A key process in this regulation is the transport of substances across cell membranes. In humans, the kidneys play a crucial role in homeostasis by regulating water and electrolyte balance.

When a person is dehydrated, the body conserves water by increasing the reabsorption of water in the kidneys. This process involves various transport mechanisms. Which of the following mechanisms is primarily responsible for the reabsorption of water in the kidneys during dehydration?