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: Pharmacology
A person developed severe vomiting after eating food from chinese restaurant, 3 hours before. Most likely causative agent is: 
Select and explain. 
A. Staph. aureus, B. B. cereus, C. C. difficle, D. Pseudomonas
B: B. cereus
Answer: B: B. cereus 
Explanation: Ans. is. 'b' i. e. B. cereus