This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Renal physiology, Subject name: Physiology
The length of distal convoluted tubule is 
Select and explain. 
A. 5 mm, B. 2 mm, C. 12 mm, D. 8 mm
A: 5 mm
Answer: A: 5 mm 
Explanation: Although the DCT is the shoest segment of the nephron, spanning only about 5 mm in length in humans (1), it plays a critical role in a variety of homeostatic processes, including sodium chloride reabsorption, potassium secretion, and calcium and magnesium handling Ref: guyton and hall textbook of medical physiology 12 edition page number:460,461,462