Which sinus is the last sinus to appear radiologically on X-ray?: (A) Maxillary sinus, (B) Sphenoid sinus, (C) Frontal sinus, (D) Ethmoidal air cells
Answer is C. Ans. is'c'i.e., Frontal sinus[Ref Textbook Of The Ear, Nose And Throat By De Soum, C. Et Al. p 394)