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
Carrom coin appearance of pneumococcus is due to 
Select and explain. 
A. Capsular polysaccharide, B. C- Carbohydrate antigen, C. Pneumolysin, D. Autolysin
D: Autolysin
Answer: D: Autolysin 
Explanation: Autolysin is amidase enzyme that cleaves peptidoglycan leading to autolysis of cells. 
This property is responsible for carrom coin appearance of pneumococcal colonies.