Collecting tube
Henle's loop
Distal convoluted tubule
Proximal convoluted tubule
In man, reabsorption of glucose occurs in the proximal convoluted tubule by active transport. The cubical cells of proximal tubules have microvilli and mitochondria to increase the surface area for absorption and active transport. It is the part of the proximal tubule. All essential nutrients and 70-80 percent of electrolytes, glucose and water are absorbed in this part. It is also involved in the selective secretion of hydrogen ions, ammonia and potassium ions into the filtrate and maintaining the pH and ionic balance of the body. So, the correct answer is option D.