This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anatomy and Physiology of Pharynx, Subject name: ENT
Passavant's ridge is formed by- 
Select and explain. 
A. Cricopharyngeus and superior constrictor, B. Palatopharyngeus and superior constrictor, C. Palatoglossus and superior constrictor, D. Thyropharyngeus and superior constrictor
B: Palatopharyngeus and superior constrictor
Answer: B: Palatopharyngeus and superior constrictor 
Explanation: Ans. is 'b' i.e., Palatopharyngeus and superior constrictor Passavant's Ridgeo Some of the upper fibres of the palatopharyngeus pass circularly deep to the mucous membrane of the pharynx, and form a sphincter internal to the superior constrictor. These fibres constitute Passavant's muscle which on contraction raises a ridge called the Passavant's ridge on the posterior wall of the nasopharynx.