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': 'All are true about arterial thrombosis except? \nSelect and explain. \nA. Retrograde growth, B. Line of Zahn, C. Complete lumen obstruction, D. White thrombus', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]