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': 'On barium swallow the grade IV esophageal varices appear as - \nSelect and explain. \nA. Mucosal folds above the carina, B. Mucosal folds below the carina, C. Mucosal folds at the carina, D. A thick band', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans is 'b' ie Mucosal folds below the carina", 'role': 'assistant'}]