Thorn wait cyst -

Ans. is 'b' i.e., Nasopharyngeal cyst Thornwaldt cvst (nasopharyngeal cyst)o A thornwaldt cyst is a benign midline nasopharyngeal mucosal cyst.o It is a developmental anomaly Which is usually asymptomatic and is found incidentally on imaging of nasopharynx. This is a notochord remnant.o Sometimes cyst may become infected and can cause halitosis or foul tasting periodic discharge into the mouth.o Asymptomatic lesions require no treatment. If treatment is required then de-roofing the cyst (marsupialization) is usually sufficient, and can be performed via a transpalatal approach.Also knowo Thornwaldt's disease is infection of pharyngeal bursa, i.e. pharyngeal bursitis