This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Oral cavity & Oesophagus, Subject name: ENT
[{'content': 'Which of the following is known as "Gateway of tears"? \nSelect and explain. \nA. Killian\'s dehiscence, B. Rathke\'s pouch, C. Waldeyer\'s ring, D. Sinus of Morgagni', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Inferior constrictor muscle has two pas: Thryopharygeus with oblique fibres Cricopharyngeus with transverse fibres Between these two pas exists a potential gap called Killian&;s Dehiscence also called "Gateway of tears" - As perforation can occur at this site during esophagectomy. (Ref: Textbook of diseases of ENT, PL Dhingra, 7th edition, pg no. 310)', 'role': 'assistant'}]