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: Surgery
[{'content': "Whitehead's varnish in gauze is used to arrest bleeding from: \nSelect and explain. \nA. Bleeding from capillaries., B. Bleeding from bone., C. Bleeding from skin., D. All of the above.", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]