Final answer:
The Daily Values represent appropriate intake levels for a 2,000-calorie diet, which is used as a reference for nutrition labeling and dietary guidelines (option a).
Step-by-step explanation:
The Daily Values represent appropriate intake levels for a 2,000-calorie diet. These values are reference amounts of nutrients to consume or not to exceed each day and are based on public health experts' advice. They are designed to help consumers make informed nutrition choices and construct an overall healthy diet. It's important to note that individual calorie needs can vary based on factors such as age, sex, weight, and physical activity level. However, the reference point for most nutrition labeling and guidance is a 2,000-calorie diet.
Hence, the answer is option a.