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
The most common cause of hypovolemic shock is 
Select and explain. 
A. Haemorrhage, B. Decreased RBC formation, C. Bone marrow suppression, D. None of the above
A: Haemorrhage
Answer: A: Haemorrhage 
Explanation: None