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': 'Tumour marker for a highly vascular tumour - \nSelect and explain. \nA. Desmin, B. Keratin, C. Sa 200, D. Alpha-feto protein', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]