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': 'Most dominant colonic bacteria is \nSelect and explain. \nA. Escherichia coli, B. Bacteroides, C. Clostridium, D. Veilonella', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Bacteroids are the normal inhabitants of the intestine, respiratory, female genital tract. the normal flora of adult colon contains 96 to99% of anaerobes and only 1 to 4% of aerobes. Anaerobes - Bacteroides species, bifidobacteria, anaerobic lactobacilli, anaerobic streptococci. Ref: Baveja textbook of microbiology; 4th edition.', 'role': 'assistant'}]