Which of the following statements is true? A food's odor or appearance is not a reliable indicator of whether it is safe to eat. The U.S. Environmental Protection Agency is responsible for inspecting local restaurants and grocery stores to ensure they meet food safety standards. In the United States, people rarely suffer from food-borne illnesses. An undercooked hamburger patty is the most likely source of aflatoxin.

The nose test is one of the most popular methods for identifying whether a food has "gone sour" in the refrigerator. The problem is that it is not a very reliable indicator. Disease-causing bacteria are intelligent because they know how to disguise themselves and do not cause a bad odor or appearance. That is, a food with a pleasant odor and appearance may not be safe to eat.

Thus, the safest thing is to identify with labels the date of preparation of homemade recipes and consume within the validity indicated by the manufacturer in the case of industrialized ones. Even if the food is on time, temperature, handling and storage conditions can cause it to spoil faster.