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
Lateral wall of mastoid antrum is related to ? 
Select and explain. 
A. Superficial temporal aery, B. External auditory canal, C. Emissary vein, D. Meningeal aery
B: External auditory canal
Answer: B: External auditory canal 
Explanation: 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.