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: Anatomy
[{'content': 'Lateral wall of mastoid antrum is related to ? \nSelect and explain. \nA. Superficial temporal aery, B. External auditory canal, C. Emissary vein, D. Meningeal aery', 'role': 'user'}, {'content': "Answer: B \nExplanation: MacEwen's triangle or suprameatal triangle overlies the lateral wall of mastoid antrum. It is bounded above by supramastoid crest, anteroinferiorly by posterosuperior margin of external auditory canal and posteriorly by a tangent drawn from zygomatic arch.", 'role': 'assistant'}]