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: Biochemistry
[{'content': 'Which vitamins are synthesised by intestinal bacteria ?a) Vit K and Db) Vit K and B12c) Vit K and H (biotin)d) Vit K and E \nSelect and explain. \nA. ab, B. bc, C. abd, D. cd', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Vitamins formed by bacterial activity are vitamin K, vitamin B12, thiamine, riboflavin and biotin (vitamin H).', 'role': 'assistant'}]