Correct Answer: D

Rationale: The primary function of protein in the body is to build and repair tissues. Proteins are crucial for growth, maintenance, and repair of body tissues, including muscles, organs, and skin. While proteins can be a source of energy, their primary role is not to supply energy. Regulating metabolic processes and controlling muscle contractions are functions typically attributed to other nutrients and compounds in the body, such as vitamins and minerals.

Correct Answer: B

Rationale: A variety of foods is the best source of nutrients because it ensures a balanced intake of all essential nutrients required by the body. Option A, specific food combinations, may not provide all necessary nutrients as relying on only a few types of food may lead to deficiencies. Option C, individual foods, also may not provide a complete range of nutrients necessary for overall health. Option D, a variety of food supplements, is not the best source of nutrients as whole foods are generally more beneficial due to their natural nutrient composition and bioavailability.

Correct Answer: D

Rationale: The correct answer is D. Dietary Reference Intakes (DRIs) are established to provide nutrient recommendations for most healthy people. They are not specific to different ethnic groups (choice A), all individuals (choice B), or most people (choice C). DRIs aim to prevent nutrient deficiencies and chronic diseases in healthy individuals by setting intake levels for various nutrients.

Correct Answer: C

Rationale: Micronutrients are essential nutrients needed by the body in small quantities to support various bodily functions. Vitamins fall under this category as they play crucial roles in metabolism, immune function, and overall health. While fats, proteins, and carbohydrates are essential macronutrients required in larger amounts for energy and growth, they are not classified as micronutrients. Therefore, the correct answer is C.

Correct Answer: C

Rationale: The correct answer is C: Healthy People 2020. Healthy People 2020 is a government initiative that sets goals for improving the health of Americans, including specific nutritional objectives. Choices A, B, and D are not examples of government nutrition policies. MyPlate Food Guidance System is a visual tool to help individuals make healthy food choices, Dietary Guidelines for Americans 2010 provide evidence-based advice for Americans two years and older, and Dietary Reference Intakes (DRIs) are a set of nutrient reference values.