This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and PNS, Subject name: ENT
Pharyngeal bursa is a site of origin for: 
Select and explain. 
A. Craniopharyngioma, B. Chordoma, C. Thornwaldt's cyst, D. Rathke's cyst
C: Thornwaldt's cyst
Answer: C: Thornwaldt's cyst 
Explanation: Infection of pharyngeal bursa gives rise to Thomwaldt's cyst which causes postnasal discharge, halitosis and occipital headache.Chordoma arises from remnants of notochord. Craniopharyngioma arises from Rathke's pouch. Rathke's cyst also arises from Rathke's pouch and can get infected, which may extend superiorly into the cranium and gives symptoms of galactorrhoea, visual loss and hypopituitarism.