This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Systemic histology, Subject name: Anatomy
[{'content': 'which is the strongest layer of oesophagus? \nSelect and explain. \nA. mucosa, B. sub mucosa, C. muscularis propria, D. adventitia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: sub mucousa is strongest layer of oesophagus and should be included in sutures', 'role': 'assistant'}]