This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
All of the following are true about connexons, EXCEPT: 
Select and explain. 
A. It is a protein, B. Has five subunits, C. Gap junction unit, D. Charcot marie tooth disease
B: Has five subunits
Answer: B: Has five subunits 
Explanation: Connexons is an assembly of six proteins called connexins. It is a unit of gap junction, helps substances to pass between cells without entering the extracellular fluid. Charcot marie tooth disease, its X linked form is said to be linked to mutant connexons. Ref: Ganong's Review of Medical Physiology, 21st Edition, Page 17