This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Anatomy
[{'content': 'A most common cause of esophageal perforation at the site of cricopharynx - \nSelect and explain. \nA. Spontoneous, B. Iatrogenic, C. Traumatic, D. None', 'role': 'user'}, {'content': "Answer: B \nExplanation: Oesophageal perforation is of two types : Iatrogenic (MC) A common site is cervical esophagus Just above the upper sphincter. Spontaneous rupture As seen in Boerhaave's syndrome (Rupture of esophagus are vomiting). Common in the lower 1/3 of esophagus. ref - Internet", 'role': 'assistant'}]