###Rationale: The onodi cells and haller cells are posterior ethmoidal air cells. Onodi cell: Posterior ethmoidal cell which may grow posteriorly by the side of sphenoid sinus or superior to it for as much distance as 1.5 cm from the anterior surface of sphenoid. Hallercells: Air cells situated in the roof of maxillary sinus. Ref.Dhingra 5/e,p 153.

###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 ethmoidal air cells
D. Orbital chiasma and Nasolacrimal duct
