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
Factor X is ? 
Select and explain. 
A. Hageman factor, B. Stua-Prower factor, C. Christmas factor, D. Tissue factor
B: Stua-Prower factor
Answer: B: Stua-Prower factor 
Explanation: Ans. is 'B' i.e., Stua-Prower factor