Which one of the following is not a vestigial structural in Homo sapiens?

Vestigial organs are degenerate, non-functional and rudimentary organs correspond to fully developed and functional organs of related organism. Third molar (wisdom teeth), plica semilunaris and pyramidalis muscles are vestigial organs. Epiglottis is not a vestigial organ in man. Epiglottis is the structure that prevents the entry of food into respiratory tract during swallowing in man.