Chilling perishable food right away, separating raw and cooked foods, and cooking meat to safe internal temperatures are all considered a way of preventing food borne illness. The answer that is not included above is thaw food in the counter. It is because the best way to handle this situation is when defrosting chilled food, it is best to do it properly and thawing it on the counter is not a good way to do it, that is why it is considered a way of not preventing food borne illnesses.