This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ocular trauma , Subject name: Ophthalmology
[{'content': '"Blow out" fracture of orbit involve - \nSelect and explain. \nA. Floor, B. Medial wall, C. Lateral wall, D. Roof', 'role': 'user'}, {'content': "Answer: A \nExplanation: These generally result from blunt trauma to the orbit by a large object such as a cricket ball, tennis ball, human fist. The force of the blow causes a backward displacement of the eyeball and an increase in the intraorbital pressure; with a resultant fracture at the weakest point of the orbital wall. Usually this point is the orbital floor , but this may be the medial wall also. Ref: Parson's 22 nd edition , page no. 499", 'role': 'assistant'}]