This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'Which is M.C. site for iatrogenic oesophageal perforation - \nSelect and explain. \nA. Abdominal portion, B. Cervical portion, C. Above arch of aorta, D. Below arch of aorta', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]