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. Gingival crest, B. Bleeding from pulp, C. Bleeding from bone, D. Bleeding from capillaries", 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]