Correct Answer: A

Rationale: The correct answer is A: Neuroblastoma. Neuroblastoma, a cancer that arises from nerve tissue, is associated with increased levels of catecholamine metabolites, including VMA and HVA, in the urine. Nephroblastoma (Wilms tumor) is a type of kidney cancer and is not typically associated with elevated levels of catecholamine breakdown products. Leukemia is a cancer of the blood and bone marrow and does not lead to increased VMA and HVA excretion in urine. Osteosarcoma is a bone cancer and is not linked to elevated levels of catecholamine metabolites in the urine.

Correct Answer: A

Rationale: Sudden and severe scrotal pain in an adolescent male is a medical emergency and may indicate testicular torsion, which requires immediate evaluation and intervention to prevent testicular loss.

Correct Answer: C

Rationale: Withdrawing and discarding a sample equal to the amount of fluid in the device ensures that the blood drawn is not diluted by the IV fluids, providing accurate lab results.

Correct Answer: C

Rationale: Mixing bitter medication with a small amount of something sweet, like jam, can mask the taste effectively without diluting the medication too much. Mixing with milk or formula is not recommended as the child may refuse future feedings, and carbonated beverages are not suitable for infants.

Correct Answer: C

Rationale: Water intoxication can lead to cerebral edema, causing neurological symptoms such as irritability and seizures. Oliguria, weight loss, and muscle weakness are not typical signs of water intoxication.