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': ". A 60-year-old man is diagnosed to be suffering from Legionnaires' disease after attending a conference. How did he acquire it? \nSelect and explain. \nA. From a chronic carrierof the disease, B. From inhalation of aerosol in the air-conditioned room at the conference, C. Following a mosquito bite at the conference, D. By sharing a towel with a fellow colleague in the conference", 'role': 'user'}, {'content': 'Answer: B \nExplanation: He most likely acquired it from inhalation of aerosol in the air-conditioned room at the conference due to cooling towers. Legionella can be found in natural, freshwater environments, but generally is not present in sufficient numbers to cause disease. Infection is typically by inhalation of aerosols produced by cooling towers, air conditioners and shower heads which act as disseminators No animal reservoirs exists, no human to human transmission occurs, and no carrier state is established. Reference: Ananthanarayan and Paniker&;s Textbook of Microbiology Tenth edition', 'role': 'assistant'}]