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
Preaccelerin is ? 
Select and explain. 
A. Eater II, B. Facter V, C. Facter VII, D. Facter X
C: Facter VII
Answer: C: Facter VII 
Explanation: Ans. is 'c' i.e., Facter VII