Correct Answer: D

Rationale: The varicella vaccine is specifically designed to prevent chickenpox. Measles, mumps, and rubella are prevented by different vaccines: Measles is prevented by the measles, mumps, and rubella (MMR) vaccine; Mumps is prevented by the MMR vaccine; and Rubella is also prevented by the MMR vaccine. Therefore, the correct answer is D, Chickenpox, as it is the disease prevented by the varicella vaccine.

Correct Answer: B

Rationale: The priority nursing intervention for a 3-year-old child with Kawasaki disease is monitoring for coronary artery aneurysms. Kawasaki disease can lead to the development of coronary artery aneurysms, which are one of the most serious complications of the disease. Early detection and monitoring of coronary artery changes are essential for prompt intervention and prevention of adverse outcomes. Administering IV immunoglobulin is an important treatment for Kawasaki disease, but monitoring for coronary artery aneurysms takes precedence as it directly impacts the child's long-term prognosis. Encouraging fluid intake and providing nutritional support are important aspects of care but are not the priority when compared to monitoring for potential life-threatening complications.

Correct Answer: B

Rationale: The correct answer is monitoring fluid balance. In a child with diabetes insipidus, the primary concern is excessive urination and fluid loss, which can lead to dehydration. Monitoring fluid balance is crucial to prevent dehydration and maintain electrolyte balance. Administering insulin (Choice A) is not indicated in diabetes insipidus, as this condition is not related to insulin deficiency. Administering diuretics (Choice C) should be avoided as it can exacerbate fluid loss in a child already at risk for dehydration. While monitoring vital signs (Choice D) is important, the priority intervention in this situation is monitoring fluid balance to prevent complications associated with dehydration.

Correct Answer: B

Rationale: Establishing a bedtime routine is the most appropriate suggestion for a parent seeking help with a child experiencing night terrors. Bedtime routines can create a sense of security and predictability for the child, potentially reducing the frequency of night terrors. Encouraging the child to talk about the night terrors (Choice A) may not be effective during the episode as the child is usually not fully awake. Allowing the child to sleep with the parents (Choice C) may inadvertently reinforce the behavior and hinder the child's ability to learn to self-soothe. Waking the child during the night (Choice D) may disrupt the sleep cycle and exacerbate the night terrors.

Correct Answer: A

Rationale: The inability to copy a square at 3 years old indicates a potential developmental delay in fine motor skills. At this age, children should be able to copy basic shapes like circles and crosses. Hopping on one foot is typically expected around the age of 4, catching a ball reliably around 5, and using a spoon effectively by 2-3 years old. Therefore, choices B, C, and D are not as indicative of a developmental delay at 3 years old as the inability to copy a square.