You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Passavant's ridge is formed by- and explain in detail?
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.