Correct Answer: C

Rationale: It is essential to give insulin at room temperature to prevent discomfort during administration. Cold insulin can cause stinging and pain, which can be avoided by allowing the insulin to reach room temperature before administration. Storing insulin in the refrigerator is correct for long-term storage, but it should be brought to room temperature before use. Rotating injection sites is important to prevent lipohypertrophy, a condition characterized by fatty lumps that can develop if injections are consistently given in the same area. Administering insulin within 30 minutes of a meal is generally recommended to match the insulin peak action with the peak glucose levels after eating, but giving insulin at room temperature is more crucial to ensure comfort and proper absorption.

Correct Answer: D

Rationale: Acute glomerulonephritis typically develops 1 to 3 weeks after a streptococcal infection, such as a sore throat, which triggers an allergic-type response that affects the glomeruli's function. This immune response leads to inflammation and damage to the glomeruli, resulting in acute glomerulonephritis.

Correct Answer: C

Rationale: The nurse should instruct the parent to rotate injection sites to prevent tissue damage and improve insulin absorption.

Correct Answer: B

Rationale: In a child with a head injury, the development of diabetes insipidus can occur due to pituitary hypofunction, leading to a deficiency of antidiuretic hormone. An elevated sodium level (hypernatremia) is a key finding in diabetes insipidus due to the excessive loss of free water in the urine, resulting in increased sodium concentration in the blood.

Correct Answer: B

Rationale: A sodium level of 140 mEq/L within the expected reference range indicates effective treatment for dehydration. In dehydration, sodium levels are often elevated, so a normal sodium level suggests that the treatment is helping to restore the electrolyte balance in the infant's body.