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
All of the following are virulence factors of peussis, except: 
Select and explain. 
A. Tracheal cytotoxin, B. Peussis toxin, C. Capsule, D. Peactin
C: Capsule
Answer: C: Capsule 
Explanation: Ans. is. 'c' i. e., Capsule