<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 33-year-old man comes to the otolaryngologist for the evaluation of a 6-month history of difficulty breathing through his nose and clear nasal discharge. He has a history of seasonal atopic rhinosinusitis. Anterior rhinoscopy shows a nasal polyp obstructing the superior nasal meatus. A CT scan of the head is most likely to show opacification of which of the following structures?? A: Pterygopalatine fossa and middle ethmoidal sinus, B: Maxillary sinus and anterior ethmoidal sinus, C: Sphenoidal sinus and posterior ethmoidal sinuses, D: Nasolacrimal duct and eustachian tube, E: Frontal sinus and anterior ethmoidal sinus,  <response>: This is a clinical vignette describing a patient with chronic rhinosinusitis presenting with nasal obstruction and discharge. The key findings are a history of atopic rhinosinusitis, anterior rhinoscopy showing a nasal polyp obstructing the superior nasal meatus, and a request for the most likely CT scan findings. The superior nasal meatus drains the posterior ethmoid sinuses, so obstruction here would likely cause opacification of the posterior ethmoids due to impaired drainage. Atopic patients are prone to develop polyps in the ethmoid sinuses. Therefore, the CT scan would most likely show opacification of the posterior ethmoid sinuses.C: Sphenoidal sinus and posterior ethmoidal sinuses 