**Core Concept**
Water reabsorption from the proximal convoluted tubule (PCT) is a critical process in renal physiology, accounting for approximately 65-70% of total water reabsorption in the nephron. This process occurs primarily in the PCT through a combination of passive and active transport mechanisms.

**Why the Correct Answer is Right**
Water reabsorption in the PCT is largely driven by the reabsorption of solutes, particularly sodium ions (Na+), which creates an osmotic gradient that facilitates the reabsorption of water. This process involves the sodium-potassium pump (Na+/K+-ATPase) in the basolateral membrane of the PCT cells, which pumps 3 Na+ ions out of the cell and 2 K+ ions into the cell, generating a negative electrical potential and a high intracellular concentration of Na+. The sodium-hydrogen exchanger (NHE3) in the apical membrane then exchanges Na+ ions for H+ ions, which are secreted into the lumen, creating an osmotic gradient that drives water reabsorption through the water channels (aquaporin-1).

**Why Each Wrong Option is Incorrect**
* **Option A:** While the loop of Henle is involved in water reabsorption, it is not the primary site of water reabsorption in the nephron.
* **Option B:** The distal convoluted tubule is also involved in water reabsorption, but it is not the primary site in the nephron.
* **Option D:** The collecting duct is involved in water reabsorption, but it is not the primary site in the nephron.

**Clinical Pearl / High-Yield Fact**
The PCT is also responsible for the reabsorption of glucose, amino acids, and other small molecules, making it a critical site for maintaining electrolyte and fluid balance.

**Correct Answer: C. Water reabsorption in the PCT is largely driven by the reabsorption of solutes, particularly sodium ions (Na+), which creates an osmotic gradient that facilitates the reabsorption of water.**