This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharynx, Subject name: ENT
The nasopharynx is lined by which epithelium? 
Select and explain. 
A. Stratified squamous nonkeratinized, B. Stratified squamous keratinized, C. Ciliated columnar, D. Cuboidal
C: Ciliated columnar
Answer: C: Ciliated columnar 
Explanation: The pharyngeal wall consists of 4 layers from within outwards 1. Mucous membrane: Epithelium is ciliated columnar in the nasopharynx and stratified squamous elsewhere 2. Pharyngeal aponeurosis (pharyngo basilar fascia ) 3. Muscular coat: 2 layers External layer - superior, middle, and inferior constrictors Internal layer - stylopharyngeus, salpingopharyngeus and palatopharyngeus muscle 4. Buccopharyngeal fascia (Ref: Diseases of ENT, PL Dhingra, 7th Edition, pg no.271)