This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
[{'content': 'The predominant colonic bacteria are \nSelect and explain. \nA. Largely aerobic, B. Largely anaerobic, C. Bacteroides, D. Staphylococci', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The normal flora of adult colon contains 96 to 99%anaerobess and only 1 to 4% of aerobs. Ref: Baveja textbook of microbiology; 4th edition. .', 'role': 'assistant'}]