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: Physiology
[{'content': 'Following constitute dietary fibres except : \nSelect and explain. \nA. Pectin, B. Cellulose, C. Hemicellulose, D. Riboflavin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: D i.e. Riboflavin', 'role': 'assistant'}]