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: Physiology
[{'content': 'Following constitute dietary fibers except \nSelect and explain. \nA. Pectin, B. Cellulose, C. Hemicellulose, D. Riboflavin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. (d) Riboflavin(Ref: Guyton, 13th ed/p.842)Classification of dietary fibersWater insoluble/less fermentedWater soluble/well fermented* Cellulose* Pectins* Hemicellulose* Gums* Lignin* Mucilages', 'role': 'assistant'}]