Final answer:
Baked potatoes are considered a potentially hazardous food due to conditions that support bacterial growth. All types of foods can be contaminated, and forgotten items like soup can show bacterial contamination due to poor storage.
Step-by-step explanation:
Among the options given, baked potatoes are considered a potentially hazardous food because they are moist, contain protein, and have a neutral or slightly acidic pH. Such conditions are ideal for the growth of bacteria if the food is not kept at the correct temperature. In contrast, saltines, bananas, and flour do not typically provide the same supportive environment for bacterial growth due to their lower moisture content or higher acidity.
It is important to be aware of food safety, especially since all types of food can potentially become contaminated. The Centers for Disease Control and Prevention (CDC) has reported Salmonella outbreaks in a variety of foods, signifying that potential contamination is not limited to a single food group. Additionally, if a soup container is left forgotten in the refrigerator and shows contamination, the contaminants are likely bacteria that have proliferated due to incorrect food storage practices.