Correct Answer: C

Rationale: One major weakness of laboratory-based studies is that results from animal testing cannot always be applied to human beings. This limitation arises due to the inherent biological differences between animals and humans, making the generalization of findings challenging. While costs may be a concern in some cases, they do not represent a universal weakness of laboratory-based studies. Findings in such studies can be replicated to ensure validity, and experimental variables can be effectively controlled in a laboratory setting. Choice C is the correct answer because the translatability of results from animal studies to humans is a significant challenge in laboratory-based research, impacting the direct application of findings to human health and well-being.

Correct Answer: B

Rationale: Encouraging joint mobility exercises is the appropriate approach to caring for a child with juvenile idiopathic arthritis (JIA). These exercises help maintain joint function and reduce stiffness, which are crucial in managing the condition. Choices A, C, and D are incorrect. Promoting weight maintenance is more relevant than weight gain as maintaining a healthy weight is important in managing JIA. Avoiding physical inactivity is not recommended as controlled and appropriate physical activities can help improve joint flexibility and overall health. Ensuring a balanced diet, which includes adequate protein, is important for overall nutrition but is not a specific intervention for managing JIA.

Correct Answer: B

Rationale: The correct answer is B, Theophylline. Theophylline is commonly used for long-term control of asthma by relaxing the muscles around the airways to keep them open, making breathing easier. Albuterol (choice A) is a short-acting bronchodilator for quick relief of asthma symptoms, not for long-term control. Ipratropium (choice C) is another short-acting bronchodilator that helps open the airways but is not typically used for long-term control. Prednisone (choice D) is a corticosteroid usually used for short periods to control asthma exacerbations or flare-ups, not as a long-term control medication.

Correct Answer: D

Rationale: The correct answer is D: Fiber. Macronutrients are nutrients required by the body in larger amounts, and they include carbohydrates, proteins, and fats. Fiber is a type of carbohydrate that falls under this category. Vitamin C (choice A) is a water-soluble vitamin, Iron (choice B) is a mineral, and Calcium (choice C) is also a mineral, not a macronutrient. Therefore, Fiber is the only macronutrient listed in the choices.

Correct Answer: D

Rationale: In hypertrophic pyloric stenosis, an olive-shaped mass can often be palpated in the infant's abdomen, which is a hallmark sign of this condition. This mass is located in the right upper quadrant of the abdomen, right of the midline. Choices A, B, and C are incorrect because while infants with hypertrophic pyloric stenosis may experience vomiting (not diarrhea), gastric pain, and irritability, and have feeding difficulties, the key assessment finding specific to this condition is the palpable olive-shaped mass in the abdomen.