**Question:** Glucose is reabsorbed in

A. Nephron's proximal convoluted tubule
B. Nephron's distal convoluted tubule
C. Nephron's collecting duct
D. Liver

**Core Concept:** Glucose reabsorption is a crucial process in maintaining glucose homeostasis in the body. In the nephron, glucose reabsorption primarily occurs in the proximal convoluted tubule (PCT) and distal convoluted tubule (DCT). Glucose is reabsorbed through the process of active transport, which is facilitated by specific transporters and enzymes.

**Why the Correct Answer is Right:** Glucose reabsorption primarily occurs in the nephron's proximal convoluted tubule (PCT) and distal convoluted tubule (DCT). In the PCT, glucose is reabsorbed through facilitated diffusion, while in the DCT, glucose is reabsorbed through active transport mediated by the sodium-glucose co-transporter (SGLT) proteins.

**Why Each Wrong Option is Incorrect:**

A. Nephron's collecting duct (CD) is incorrect because glucose reabsorption occurs in the PCT and DCT, not in the CD. Glucose reabsorption in the CD primarily occurs for water reabsorption and electrolyte regulation.

B. Nephron's distal convoluted tubule (DCT) is incorrect because glucose reabsorption occurs in the PCT and DCT, not just the DCT. The DCT is primarily responsible for reabsorbing sodium and maintaining electrolyte balance, not glucose reabsorption.

C. Liver is incorrect because glucose regulation primarily occurs in the liver through glycogenesis, gluconeogenesis, and glycogenolysis. The liver plays a crucial role in blood glucose homeostasis, but glucose reabsorption in the nephron is not related to the liver.

D. None of the above is incorrect because none of the given options accurately describe the specific nephron segment responsible for glucose reabsorption. The correct answer is A, B, and C.

**Clinical Pearl:** Understanding the specific nephron segments involved in glucose reabsorption is essential for understanding the regulation of glucose homeostasis and the roles of the kidneys in maintaining glucose balance in the body. Nephron segments like PCT, DCT, and CD all contribute to electrolyte and water regulation, but specific focus on glucose reabsorption lies in the PCT and DCT.