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.

Correct Answer: B

Rationale: The ventrogluteal site is free of significant nerves and vascular structures, making it a safer choice for intramuscular injections in young children compared to other sites that may be more prone to complications.

Correct Answer: D

Rationale: Early signs of aspirin poisoning include hyperventilation due to the stimulation of the respiratory center and the resultant respiratory alkalosis. Hematemesis, hematochezia, and hyperglycemia can occur later in the poisoning process or may not be directly related to aspirin toxicity.

Correct Answer: A

Rationale: A bone marrow aspirate is the definitive test to confirm acute lymphoblastic leukemia (ALL) in this case. It allows for the examination of leukemic cells in the bone marrow, providing a direct assessment of the disease. Red blood cell count (Choice B) is not specific for diagnosing leukemia but may show anemia commonly seen in leukemia patients. Lumbar puncture (Choice C) is used to assess central nervous system involvement, not primarily for confirming ALL. Bone scan (Choice D) is not a standard diagnostic test for ALL and is mainly used for evaluating bone metastases in other conditions.

Correct Answer: B

Rationale: Hypotonic dehydration occurs when the loss of electrolytes exceeds the loss of water, leading to a decrease in plasma osmolarity. This often occurs when sodium loss is greater than water loss, as in diarrhea or vomiting.