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
[{'content': 'A mechanic working on a car accidently cut his finger and begins to bleed. Which endogenous molecule will initiate the process of hemostasis? \nSelect and explain. \nA. Calcium, B. Thromboxane A2, C. Nitrous oxide, D. Endothelium', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Endothelium injury\xa0→ Releases tissue factor\xa0→ Procoagulants enter circulation', 'role': 'assistant'}]