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': 'Blow out fracture of the orbit, most commonly leads to fracture of - \nSelect and explain. \nA. Posteromedial floor of orbit, B. Medial wall of orbit, C. Lateral wall of orbit, D. Roof of orbit', 'role': 'user'}, {'content': 'Answer: A \nExplanation: "The most common site for a blowout fracture to occur is the posteromedial aspect of the orbital floor, medial to the infraorbital neurovascular bundle where the maxillary bone is very thin." - The Internet Journal of Otorhinolaryngology.', 'role': 'assistant'}]