This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
Food poisoning with incubation period less than 6 hours is due to - 
Select and explain. 
A. V. Cholerae, B. Bacillus cereus, C. Clostridium prefringens, D. Salmonella
B: Bacillus cereus
Answer: B: Bacillus cereus 
Explanation: Bacillus cereus produces at least 2 distinct enterotoxins, causing two distinct form of food poisoning. Emetic form : incubation period - 1-6 hrs Diarrhoeal form: incubation period - 12-24 hrs V.chloerae - incubation period - commonly 1-2 days Clostridium perfringens -incubation period - 6-24 hrs Salmonella - incubation period - 12-24 hrs Ref: PARK&;S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE 23rd edition , Page 239