This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Medicine
[{'content': 'Hydrogen breath test is/ae used for \nSelect and explain. \nA. Lactose intolerance, B. GERD, C. H.Pylori, D. Irritable bowel syndrome', 'role': 'user'}, {'content': 'Answer: A \nExplanation: <p>Davidson&;s principles and practice of medicine 22nd edition. *The lactose hydrogen breath test is an useful non invasive confirmatory investigation. <p>', 'role': 'assistant'}]