What is the "use by date" primarily concerned with?

The "use by date" is primarily concerned with food safety. It indicates the date by which a product should be consumed to ensure it is safe to eat. After this date, there is a higher risk of harmful bacteria multiplying to unsafe levels, which could lead to foodborne illnesses. This date is particularly important for perishable items, such as dairy products, meat, and prepared foods that require refrigeration.

In contrast, while the other options pertain to aspects of food quality and freshness, they do not relate directly to safety. For instance, the quality of the food and when it is at its best refer to the taste and texture of the food, which can often extend beyond the use by date in some cases. The retail sale date concerns when the product should be available for consumers, but it does not address safety as clearly as the use by date. Therefore, understanding the use by date is crucial for ensuring consumer safety regarding the consumption of food products.