This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Infection, Subject name: Medicine
Most common cause of surgical wound infection is: 
Select and explain. 
A. Staph aureus, B. Streptococcus, C. Pseudomonas, D. Anaerobes
A: Staph aureus
Answer: A: Staph aureus 
Explanation: Ans: aRef: Harrison, 16thed, p. 778