This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
[{'content': 'Esophagus is present in which mediastinum \nSelect and explain. \nA. Anterior, B. Posterior, C. Middle, D. Lateral', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Oesophagus is present in posterior mediastinum B D CHAURASIA&;S HUMAN ANATOMY UPPER LIMB THORAX-VOLUME-1 SIXTH EDITION Page no-247', 'role': 'assistant'}]