This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inborn Errors of Metabolism, Subject name: Pediatrics
[{'content': 'Lactose intolerance in a suspected patient is diagnosed by giving an oral load of lactose and measuring concentration of: \nSelect and explain. \nA. CO2, B. H2, C. One/two carbon compounds, D. N2', 'role': 'user'}, {'content': "Answer: B \nExplanation: b. H2 (Ref: Nelson's 20/e p 2870, Ghai 8/e p 297)Breath hydrogen tests can be used to determine a specific carbohydrate malabsorption.It can be used to diagnose bacterial overgrowth or lactose/fructose malabsorption.", 'role': 'assistant'}]