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': 'Cock’s peculiar tumour is \nSelect and explain. \nA. infected sebaceous cyst, B. osteomyelitis of skull, C. cyst in the skull, D. tumour of the skull', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]