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': 'All the following are congenital cysts except \nSelect and explain. \nA. External angular dermoid cyst, B. Sebaceous cyst, C. Branchial cyst, D. Thyroglossal cyst', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]