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': "A 70 year old patient comes with symptoms of achalasia from 3 months. Radiologic features and manometric studies show the typical features of achalasia. What is the next step \nSelect and explain. \nA. CT scan, B. Heller's myotomy, C. Nissens fundoplication, D. 24 hour ph monitoring", 'role': 'user'}, {'content': 'Answer: A \nExplanation: This might be the case of pseudo achalasia. It is suspected when\n\nPatient older than 60\nDysphagia less than 6 months\nExcessive weight loss\n\nSometimes infiltrating tumor at gastroesophageal junction will mimic achalasia symptoms and manometric studies. To rule out tumor CT scan must be done', 'role': 'assistant'}]