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': 'The trismus following a lower molar extraction after 4 weeks may be due to: \nSelect and explain. \nA. Breakage of needle in pterygomandibular space, B. Hematoma of TMJ, C. Submassetric space abscess, D. Root stump in the socket', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]