This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Pathology
von Willebrand factor is produced by - 
Select and explain. 
A. Liver, B. Platelets, C. Endothelial cells, D. Spleen
C: Endothelial cells
Answer: C: Endothelial cells 
Explanation: Von willebrand factor is produced endothelial cells.It is produced to a lesser degree by megakaryocytes. But mainly by endothelial cells Ref:Robbins and Cotran Pathologic basis of disease.South Asia Edition volume 1. Page no.662