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
Which is not a capsulated organism 
Select and explain. 
A. Pneumococcus, B. Bacillus anthracis, C. H influenza, D. Clostridium tetani
D: Clostridium tetani
Answer: D: Clostridium tetani 
Explanation: All clostridia are non-capsulated except clostridium perfringens.