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
Waterhouse -Friderichsen syndrome is caused by which of the following organisms? 
Select and explain. 
A. Streptococcus Pyogenes, B. Neisseria Meningitidis, C. Clostridium Perfringens, D. Staphylococcus Aureus
B: Neisseria Meningitidis
Answer: B: Neisseria Meningitidis 
Explanation: Also called as fulminant meningococcemia. It is a fatal condition characterised with shock, DIC, multisystem failure. Ref: Ananthanarayan and Panicker's, 8th Edition, Page 225