Correct Answer: B

Rationale: The peak age for the onset of minimal change nephrotic syndrome (MCNS) is typically between 4 and 5 years old. MCNS is the most common cause of nephrotic syndrome in children, particularly within this age range.

Correct Answer: B

Rationale: A sunken fontanel is a classic sign of dehydration in infants, indicating a fluid volume deficit. In dehydration, the fontanel sinks due to decreased fluid volume in the body. Increased blood pressure (Choice A) is not typically associated with dehydration in infants. Decreased pulse rate (Choice C) is not a common finding in fluid volume deficit, as the body tries to increase the heart rate to compensate for decreased volume. Low urine specific gravity (Choice D) may be seen in dehydration, but it is not as specific or as easily observable as a sunken fontanel.

Correct Answer: C

Rationale: The correct answer is C: Autonomy vs. shame and doubt. Erikson's developmental stage for toddlers focuses on the conflict between developing a sense of independence (autonomy) and feelings of inadequacy (shame and doubt). Encouraging toddlers to explore their environment and make choices helps them build self-confidence and independence. Choices A, B, and D are incorrect because trust vs. mistrust relates to infancy, industry vs. inferiority is associated with school-age children, and initiative vs. guilt is linked to preschoolers.

Correct Answer: C

Rationale: The symptoms of gagging and drooling suggest that the foreign object is likely lodged in the esophagus. This can cause significant discomfort and potential complications, requiring immediate medical evaluation.

Correct Answer: C

Rationale: Renal transplantation is the preferred method of treatment for children with end-stage renal disease, as it offers the best chance for a normal lifestyle compared to long-term dialysis. Transplantation can be performed at any age, and kidneys can come from adult donors as well.