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: Medicine
Bernard soluier syndrome is due to defective 
Select and explain. 
A. Platelet adhesion, B. Platelet aggregation, C. Platelet secretion, D. Platelet sequestration
A: Platelet adhesion
Answer: A: Platelet adhesion 
Explanation: None