This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thoracic Duct & Esophagus, Subject name: Anatomy
[{'content': 'Cervical part of esophagus all are true except- \nSelect and explain. \nA. Arise at cricoid level, B. Site of portosystemic anastomosis, C. Foreign body obstruction common at this level, D. Striated muscle fibres positive', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Site of portosystemic anastomosis o Portosystemic (Porto caval) anastomosis is seen in lower part (abdominal part) of esophagus,o Cervical esophagus begins at lower border of cricoid cartilage (at C$ vertebral level) as a downward continuation of pharynx.o Muscularis externa of cerv ical esophagus contains only skeletal muscle (striated muscle) fibers,o Foreign body obstruction is common in this part of esophagus.", 'role': 'assistant'}]