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
Which is responsible for adhesion of platelet on exposed collagen fibril after an injury 
Select and explain. 
A. Von willebrand factor, B. Factor 8, C. Factor 9, D. Fibronectin
A: Von willebrand factor
Answer: A: Von willebrand factor 
Explanation: None