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
[{'content': 'Passavant ridge is formed by- \nSelect and explain. \nA. Tensor veli palatini and superior constrictor, B. Palatopharyngeous and superior constrictor, C. Palatopharyngeous and inferior constrictor, D. Palatoglossus and superior constrictor', 'role': 'user'}, {'content': "Answer: B \nExplanation: 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.\nThese fibres constitute Passavant's muscle which on contraction raises a ridge called the Passavant's ridge on the posterior wall of the nasopharynx.", 'role': 'assistant'}]