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
Virulence factor of group. A beta hemolytic streptococci - 
Select and explain. 
A. P. M, B. P. T, C. P. R, D. Lipotechoic acid
A: P. M
Answer: A: P. M 
Explanation: Ans. is 'a' i.e., P. M M protein is the most impoant virulent factor for str. pyogenes.