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: Ophthalmology
[{'content': 'A teenager brought with blow out fracture of orbit. The fracture may involve mainly: \nSelect and explain. \nA. Roof of the orbit, B. Posterior wall of floor of orbit, C. Medial wall of orbit, D. Medial pa of floor of orbit', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Blowout fractures mainly involve orbital floor and medial wall. When an external force is applied to the globe, intraorbital pressure increases to the point that one or more of the thin-walled bones of the orbit "blow-out" or fracture. The most common bone fractured is the maxillary bone which comprises the floor of the orbit. The orbital contents can be significantly displaced inferiorly after orbital blowout fracture. Ref: Shirakbari A.A., Hall M. (2011). Chapter 23. Maxillofacial & Neck Trauma. In R.L. Humphries, C. Stone (Eds), CURRENT Diagnosis & Treatment Emergency Medicine, 7e.', 'role': 'assistant'}]