All open into middle meatus except ?: (A) Frontal sinus, (B) Sphenoid sinus, (C) Maxillary sinus, (D) Ethmoidal sinus
Answer is B. Ans. is 'b' i.e., Sphenoid sinus Pa of lateral nasal wallOpeningsInferiorNasolacrimal ductMiddleFrontal sinus, Maxillary sinus, Anterior ethmoidal sinusSuperiorPosterior ethmoidal sinusSphenoethmoidal recessSphenoid sinus