Correct Answer: A

Rationale: The correct answer is A: 'nutrient reserves are depleted.' Signs of malnutrition manifest when the body's reserves of essential nutrients are exhausted and can no longer sustain health. Choice B is incorrect because excessive nutrient intake exceeding daily needs does not lead to malnutrition but may cause other health issues. Choice C is incorrect as restricting energy intake may lead to weight loss but not necessarily malnutrition. Choice D is also incorrect as increasing caloric expenditure does not directly cause malnutrition.

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: D

Rationale: The Tolerable Upper Intake Level (UL) represents the highest amount of a nutrient that can be safely consumed without causing adverse health effects. It is not a replacement for Recommended Dietary Allowances (RDAs) (choice A) which are nutrient intake recommendations. While the UL is established to prevent toxicity, it is not a completely safe level for people of all ages (choice B). It is also not a potentially toxic level of intake of a nutrient (choice C), but rather the level that is unlikely to cause adverse health effects.

Correct Answer: A

Rationale: Carbohydrates are the body's primary source of energy. When carbohydrates are consumed, they are broken down into glucose, which is used by the body's cells for energy production. Fats and proteins are also essential nutrients, but carbohydrates are the preferred energy source for the body due to their quick conversion into fuel. Vitamins are not a direct source of energy but play crucial roles in various bodily functions.

Correct Answer: A

Rationale: The correct answer is A: Longitudinal and circular. Longitudinal and circular muscles are responsible for the movements that help propel food through the intestine. Choice B, expulsion and traction, is incorrect as these terms do not specifically relate to the types of muscular movement in the intestine. Choice C, tonus and clonus, refers to different types of muscle contractions and are not the primary movements in the intestine. Choice D, intermittent and continuous, does not accurately describe the specific types of muscular movement that occur in the intestine.