Which of the following is a common cause of food poisoning?

• A. Water hardness.
• B. Air humidity.
• C. Bacteria or their toxins.
• D. Vitamin deficiency.

Answer: (C)

Food poisoning mainly comes from biological hazards, especially bacteria and the toxins they can produce. Pathogens like Salmonella, Campylobacter, E. coli, and Staphylococcus aureus contaminate food through improper handling, undercooking, or poor storage, and some of them release toxins that cause illness. That’s why controlling biological hazards is central in HACCP—by cooking foods to safe temperatures, cooling promptly, preventing cross-contamination, and keeping good hygiene, you reduce the risk from these bacteria and their toxins. The other options don’t directly cause poisoning in the same way: water hardness and air humidity can affect spoilage and quality, but aren’t typical direct causes of foodborne illness, and vitamin deficiency relates to nutrition, not poisoning from contaminated food.