This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bleeding Disorders, Subject name: Pathology
Which plasma protein is necessary for adhesion of platelets to subendothelialfibres? 
Select and explain. 
A. Glycoprotein IIb, B. Von Willebrand factor, C. Platelet factor 3, D. Factor X
B: Von Willebrand factor
Answer: B: Von Willebrand factor 
Explanation: Ans. (b) Von Willebrand factor(Ref: Robbins 9th/pg 661)Von Willebrand factor is necessary for adhesion of platelets to subendothelial fibres.