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: 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: C

Rationale: Public health nutritionists work within communities to ensure that populations have access to nutritional resources. They focus on promoting good nutrition, developing programs, and educating the public about healthy eating habits. While community physicians, public health nurses, and registered dietitians may also play roles in promoting nutrition in the community, the primary responsibility for nutrition care typically falls under the purview of public health nutritionists.

Correct Answer: C

Rationale: The recommended fat intake is between 20% to 35% of total daily calories. This range is considered optimal for maintaining a healthy diet. Choice A (10% to 15%) is too low and might not provide enough essential fats for the body. Choice B (10% to 35%) includes an upper limit that exceeds the generally accepted range. Choice D (40% to 55%) suggests a fat intake that is higher than what is recommended, which could lead to health issues if consumed regularly.

Correct Answer: B

Rationale: The correct answer is B: the unhealthy American public. The 2010 Dietary Guidelines primarily aimed to address the unhealthy eating habits prevalent in the American population. Choice A is incorrect as the focus was not solely on generally healthy segments of the population. Choice C is incorrect as the guidelines were not specifically tailored only for vulnerable population segments. Choice D is incorrect as the guidelines were more concerned with promoting healthy eating habits rather than ethnically diverse eating styles.