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: Microbiology
[{'content': 'Which of the following is late lactose fermenter: \nSelect and explain. \nA. E. coli, B. Klebsiella, C. Salmonella, D. Shigella sonnei', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is. 'd' i. e., Shigella sonnei", 'role': 'assistant'}]