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': 'Waterhouse-Friderichsen syndrome is caused by \nSelect and explain. \nA. Neisseria, B. Chlamydia, C. Hemophilus influenza type b, D. Listeria', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Meningococcemia sometimes occurs without meningitis and may progress to fulminant DIC and shock with bilateral hemorrhagic destruction of the adrenal glands (Waterhouse-Friderichsen syndrome).Ref: Sherris microbiology; 6th edition; Page no: 540', 'role': 'assistant'}]