This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2018, Subject name: Ophthalmology
[{'content': 'Blow out fracture can be due to: \nSelect and explain. \nA. Tennis ball injury, B. Chisel and hammer injury, C. Sudden fall, D. Punch at the chin from below', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Blow out orbital fracture result from trauma to orbit by a relatively large often rounded object such as tennis ball, cricket ball, human fist, or a pa of automobile.The force of blow causes a backward displacement of the eyeball and increase in the intraorbital pressure. CLASSIFICATION 1 PURE BLOW OUT FRACTURE - NOT associated with involvement of the orbital rim 2 Impure blow out - associated with other fractures about the middle third of facial skeleton - Inferior wall M/C involved - Entrapment of inferior rectus in inferior wall - not able to look up- Hanging drop or tear drop sign Features (1) Enophthalmos (2 ) Diplopia(3) Infra orbital nerve anesthesia', 'role': 'assistant'}]