One of the following opens into middle meatus of nose: (A) Naso-lacrimal duct, (B) Eustachian tube, (C) Sphenoidal sinus, (D) Maxillary sinus
Answer is D. The middle meatus presents the ethmoidal bulla,the hiatus semilunaris,the infundibulum and the opening of frontal,maxillary and the middle ethmoidal air sinuses.Sphenoidal air sinus opens into the sphenoethmoidal recess,which is a triangular fossa just above the superior concha. REF.BDC VOL.3,5th edition.