This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
Passavant ridge is formed by- 
Select and explain. 
A. Tensor veli palatini and superior constrictor, B. Palatopharyngeous and superior constrictor, C. Palatopharyngeous and inferior constrictor, D. Palatoglossus and superior constrictor
B: Palatopharyngeous and superior constrictor
Answer: B: Palatopharyngeous and superior constrictor 
Explanation: 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.