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: Medicine
[{'content': "Recurrence rate is highest with which modality of treatment for achalasia cardia - \nSelect and explain. \nA. Pneumatic dilatation, B. Botulinum toxin injection, C. Heller's operation, D. Laparoscopic myotomy of sphincter", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]