This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2018, Subject name: ENT
[{'content': 'Optic nerve injury following sinus surgery is due to removal of which ethmoidal cells? \nSelect and explain. \nA. Haller, B. Agger nasi, C. Onodi cells, D. Bullae cells', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Onodi cell "Onodi cell" is the posterior most posterior ethmoid cell extending lateral to the sphenoid sinus. While removing disease from the Onodi cells there are chances of injury to optic nerve and internal carotid which lie in the vicinity. The posterior ethmoidal cells in the floor of orbit are known as "Haller cells".', 'role': 'assistant'}]