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
C.tetani is: 
Select and explain. 
A. Aerobic, gram-positive, motile bacillus, B. An anaerobic, gram-negative, motile bacillus, C. An anaerobic, gram-positive, nonmotile bacillus, D. An anaerobic, gram-positive, motile bacillus
D: An anaerobic, gram-positive, motile bacillus
Answer: D: An anaerobic, gram-positive, motile bacillus 
Explanation: An anaerobic, gram-positive, motile bacillus