###Rationale: "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".

###Answer: OPTION A IS CORRECT.
###Question: Onodi cells and haller cells are seen in relation to:
###Options:
A. Optic nerve and floor of orbit
B. Optic nerve and frontal sinus
C. Optic nerve and ethmoid air cells
D. Optic chiasma and nasolacrimal duct
