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: Medicine
A 22 year old man had a Beef sandwich and Potato salad. He Vomited 2 hours after the meal. What is the probable diagnosis 
Select and explain. 
A. S. aureus poisoning, B. Bacillus cereus poisoning, C. Clostridial poisonong, D. Helicobacter pylori poisoning
A: S. aureus poisoning
Answer: A: S. aureus poisoning 
Explanation: Preformed toxin of S. aureus causes nausea within 1-6 hours of ingestion.
Common food associated are: Poultry, potato and egg salad.