Correct Answer: B

Rationale: The correct answer is B. Magnesium plays an important role in maintaining calcium homeostasis and preventing skeletal abnormalities. It is involved in more than 300 enzymatic reactions, including energy metabolism, insulin activity, and glucose use. Magnesium is vital to the structural integrity of heart muscle and other muscles and nerves. While magnesium does play a role in blood clotting, nerve impulses, muscle contraction, relaxation, ATP energy release, and metabolism of fats, carbohydrates, proteins, the primary physiologic role of magnesium in the body is related to calcium homeostasis and maintaining the structural integrity of the heart muscle. Choice A is incorrect because it includes functions of magnesium, but they are not its primary physiologic role. Choice C is incorrect as magnesium has several known metabolic functions. Choice D is incorrect because although magnesium is involved in ATP energy release and metabolism, its primary role is related to calcium homeostasis and structural integrity of muscle.

Correct Answer: A

Rationale: Both statements are true. Approximately 75% of reputable producers of bottled water use groundwater as their water source, which is the same source as the public water supply. Plain tap water, coming from underground sources or reservoirs, is indeed a natural source of fluids. The first statement is supported by the fact that groundwater is a common source for bottled water due to its purity and taste. The second statement is true as tap water is sourced from natural reservoirs or underground aquifers in most cases, making it a natural fluid source for consumption. Other choices are incorrect because both statements are factually accurate based on common practices in the production and sourcing of bottled water and tap water.

Correct Answer: C

Rationale: The correct answer is C. The first statement is true as the nutrient facts panel was indeed established by the USDA and the FDA to improve health and well-being by enhancing nutritional knowledge. However, the second statement is false. Nutrient content claims actually refer to the amount of a nutrient in a food, not to the relationship between a food and disease risk. Therefore, the second statement is incorrect, making choice C the correct option. Choice A is incorrect because the second statement is false. Choice B is incorrect as the first statement is true. Choice D is incorrect because the second statement is false.

Correct Answer: A

Rationale: The correct answer is A: Elderly. The other choices provided, low income, vegans, and chronic disease, alcoholics, are also at risk for nutritional deficiencies but the question specifically asks for 4 groups out of the 12 discussed. The 12 groups at risk for nutritional deficiencies include the elderly, low income individuals, vegans, chronic disease, alcoholics, smokers, periods of growth, individuals with medical conditions, physical stress, physiological stress, those on polypharmacy, and those with inadequate intake. The question focuses on identifying 4 out of these 12 groups, making 'Elderly' the correct choice.

Correct Answer: C

Rationale: The first statement is true; the second is false. Complex carbohydrates are also called polysaccharides and contain more than 10 monosaccharides. Choice A is incorrect because the second statement is false. Choice B is incorrect because the first statement is true. Choice D is incorrect because the second statement is false.