This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General physiology, Subject name: Physiology
Most permeable to pure phospholipid bilayer 
Select and explain. 
A. Oxygen, B. Na, C. Cl, D. Water
A: Oxygen
Answer: A: Oxygen 
Explanation: Phospholipid bilayer act as amphipathic molecule. Oxygen is most permeable. (REF. GANONG&;S REVIEW OF MEDICAL PHYSIOLOGY 24 EDITION, PAGE NO - 36)