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
All endothelial cells are involved in the production of thrombomodulin EXCEPT those found in: 
Select and explain. 
A. Hepatic circulation, B. Cutaneous circulation, C. Cerebral microcirculation, D. Renal circulation
C: Cerebral microcirculation
Answer: C: Cerebral microcirculation 
Explanation: Endothelium of the blood vessels plays an active role in preventing the extension of clots into blood vessels. All endothelial cells except those in the cerebral circulation produce thrombomodulin. Ref: Review of Medical Physiology By Ganong, 22nd Edition, Page 543; Robbins Pathologic Basis of Disease, 6th Edition, Page 120