Correct Answer: B

Rationale: The correct answer is B. In a double-blind experiment, neither the subjects nor the researchers know which subjects are in the control or experimental group. This helps to eliminate bias and ensure that the results are more objective. Choice A is incorrect as in a double-blind experiment, subjects do not take turns receiving each treatment; it is about masking the treatment allocation. Choice C is incorrect because it implies that the researchers are aware of the group allocation, which goes against the principle of blinding in a double-blind study. Choice D is incorrect as both subject groups should not know whether they are in the control or experimental group to maintain the blindness of the study.

Correct Answer: B

Rationale: The correct answer is B. In a double-blind experiment, neither the subjects nor the researchers know which subjects are in the control or experimental group. This helps to eliminate bias and ensure that the results are more objective. Choice A is incorrect as in a double-blind experiment, subjects do not take turns receiving each treatment; it is about masking the treatment allocation. Choice C is incorrect because it implies that the researchers are aware of the group allocation, which goes against the principle of blinding in a double-blind study. Choice D is incorrect as both subject groups should not know whether they are in the control or experimental group to maintain the blindness of the study.

Correct Answer: D

Rationale: Glucose is the correct answer as it is the primary source of energy for the brain and nervous system. The brain relies heavily on glucose to function optimally. While protein and fat play essential roles in the body, they are not the primary sources of energy for the brain and nervous system. Carbohydrates, on the other hand, are broken down into glucose, which is then used as fuel by the brain and nervous system.

Correct Answer: D

Rationale: The Recommended Dietary Allowances (RDAs) are the best measure to describe the amounts of nutrients that should be consumed by the population. RDAs represent the average daily intake level that meets the nutrient requirements of nearly all (97-98%) healthy individuals in a particular life stage and gender group. Choice A, the Dietary Reference Intakes, provide a set of nutrient intake values but do not specifically address the average daily amount of a nutrient considered adequate for practically all individuals. Choice B, the Tolerable Upper Intake levels, focus on the maximum daily amount of a nutrient deemed safe for most healthy people, not the average daily amount needed. Choice C, the Estimated Average Requirements, reflect the average daily amount of a nutrient needed by half of the healthy individuals, which is not as comprehensive as the RDAs that cater to nearly all healthy people.

Correct Answer: B

Rationale: When administering medications to a child with hepatic dysfunction, it is crucial to make adjustments in dosage due to altered metabolism. Hepatic dysfunction can affect the way medications are metabolized in the body, potentially leading to drug toxicity or reduced effectiveness. This is why adjusting the dosage is essential to ensure the medication is both safe and efficient. Choices A, C, and D are incorrect because increasing dosing intervals, avoiding all medications, or using only topical medications do not address the specific issue of altered drug metabolism in hepatic dysfunction.