Correct Answer: C

Rationale: Severe dehydration is the most common cause of acute renal failure in children, as it leads to prerenal azotemia, which can progress to renal failure if not corrected. Other causes like pyelonephritis and tubular destruction are less common and usually secondary to other conditions.

Correct Answer: A

Rationale: Renal ultrasonography provides imaging of the renal parenchyma and pelvis without the risks associated with radiation or radioactive isotopes, making it a safer option, especially for children.

Correct Answer: D

Rationale: The effectiveness of prednisone in treating MCNS is indicated by diuresis and a decrease in urinary protein excretion. Subsidence of generalized edema is also a positive sign, but the key indicator is the reduction in proteinuria, which is achieved through diuresis.

Correct Answer: C

Rationale: The primary objective in managing MCNS is to minimize the excretion of urinary protein, which is responsible for the hypoalbuminemia and subsequent edema in these patients.

Correct Answer: D

Rationale: ESRD places significant stress on both the child and the family due to the ongoing need for dialysis, medications, and lifestyle restrictions, making it important for healthcare providers to offer extensive support and resources to manage these challenges.