Which of the following is MOST impoant in separating the esophagus from the larynx, and must consequently be carefully passed behind during endoscopy?

Endoscopists are very careful when guiding the endoscope past the epiglottis, which is a pear-shaped poion of elastic cailage that can be moved during swallowing to close the larynx, preventing swallowed material from eventually entering the lungs.The arytenoids are the site of the attachment of the vocal cords within the larynx.The cricoid cailage is in the more distal poion of the larynx.The pharynx is shared by the respiratory and gastrointestinal tracts.Also know:The thyroid cailage forms a median elevation, called the laryngeal prominence ("Adam's apple"), and lies inferior to the hyoid bone.The epiglottis is an elastic cailage, shaped like a spoon, that is posterior to the root of the tongue.The cricoid cailage is shaped like a signet ring, with the broad pa of the ring facing posteriorly.The arytenoid cailages are shaped like a pyramid.