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: Pathology
Procoagulant factors produced by endothelial cells include 
Select and explain. 
A. Thrombomodulin, B. Prostacyclin, C. Von Willebrand factor, D. von Willebrand factor
C: Von Willebrand factor
Answer: C: Von Willebrand factor 
Explanation: The three main components of hemostasis include endothelial cells, platelets, and the coagulation system. Endothelial cells exhibit both procoagulant and anticoagulant properties. Their procoagulant activities involve activation of the extrinsic coagulation cascade by their production of tissue factor (thromboplastin) and stimulation of platelet aggregation by their production of von Willebrand factor and platelet-activating factor.