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
Non-motile organism: 
Select and explain. 
A. E. coli, B. Vibrio cholera, C. Protein in nature, D. Antigenic
D: Antigenic
Answer: D: Antigenic 
Explanation: Ans. d. Antigenic