Correct Answer: A

Rationale: Infection is the greatest risk for an infant with exstrophy of the bladder due to the exposure of the bladder and surrounding tissues. The exposed bladder increases the risk of infection as it lacks the protective covering of the skin. Dehydration (Choice B) may occur but is not the greatest risk compared to infection. Urinary retention (Choice C) is less likely due to the nature of the condition. Intestinal obstruction (Choice D) is not directly associated with exstrophy of the bladder.

Correct Answer: B

Rationale: It is recommended that a child should visit the dentist within the next few months after turning two years old. This allows for early dental check-ups to monitor oral health, detect any issues early on, and establish a good oral hygiene routine. Choice A ('Before starting school') is not as specific and may delay the child's first dental visit. Choice C ('When the first deciduous teeth are lost') is too late for the first dental visit, as preventive care should start earlier. Choice D ('At the next dental visit of a family member') is not ideal as the child's dental needs should be addressed independently of family members' visits.

Correct Answer: B

Rationale: The correct answer is B: Tissue oxygen needs. Polycythemia occurs in response to chronic hypoxia, leading the body to increase red blood cell production to enhance oxygen delivery. In tetralogy of Fallot, a congenital heart defect that results in reduced oxygen levels in the blood, the body compensates by producing more red blood cells. Choice A is incorrect as low tissue oxygen needs would not trigger polycythemia. Choice C, diminished iron levels, is not the cause of polycythemia in this case. Choice D, hypertrophic cardiac muscle, is unrelated to the pathophysiology of polycythemia in tetralogy of Fallot.

Correct Answer: D

Rationale: Elevating the head of the bed is essential in the care of an infant with RSV as it helps improve breathing by reducing congestion and promoting drainage. This position also aids in maintaining patent airways and can enhance comfort for the infant. Providing small, frequent feedings (Choice A) is generally appropriate for infants but is not a specific intervention for RSV. Administering antibiotics (Choice B) is not indicated for RSV, as it is a viral infection and antibiotics are ineffective against viruses. Maintaining strict isolation (Choice C) is important to prevent the spread of infections, but it is not a direct care intervention for managing RSV symptoms.

Correct Answer: B

Rationale: Limiting screen time is a crucial recommendation to prevent childhood obesity. Excessive screen time is associated with sedentary behavior and increased consumption of unhealthy snacks, leading to weight gain. Encouraging high-calorie snacks (Choice A) contradicts the goal of preventing obesity. While fast food as a treat (Choice C) can be consumed occasionally, it should not be encouraged as a regular practice. Allowing the child to eat freely (Choice D) without restrictions can lead to overeating and unhealthy dietary habits, contributing to obesity risk.