This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Staphylococci, Subject name: Microbiology
Most common biotype of S. aureus causing human infection- 
Select and explain. 
A. B, B. C, C. D, D. A
D: A
Answer: D: A 
Explanation: Ans. is 'D' i.e., A o Staphylococcus aureus has been classified into six biotypes : A, B, C, D, E and F. o Most human pathogenic strains belong to biotype A.