Correct Answer: C

Rationale: Isolating the child is a priority to prevent the spread of infection until meningitis is confirmed or ruled out. Meningitis, particularly bacterial, is highly contagious and can lead to outbreaks if not properly managed. Isolation and prompt treatment are critical in preventing serious complications. Administering antibiotics immediately without confirmation of the diagnosis can be harmful if the cause is viral or non-infectious. Performing a lumbar puncture is a diagnostic procedure that should be done by a healthcare provider but is not the initial action when suspecting meningitis. Obtaining a complete blood count may be part of the diagnostic workup but is not the most appropriate initial action in suspected meningitis.

Correct Answer: B

Rationale: Hypokalemia is the correct answer because it is a common concern in children with severe diarrhea. Diarrhea can lead to significant potassium loss, resulting in hypokalemia. Hypernatremia (Choice A) is less common in diarrhea as sodium concentration is usually diluted by the fluid loss. Hypercalcemia (Choice C) is not typically associated with severe diarrhea. Hypomagnesemia (Choice D) can occur but is not as common as hypokalemia in this scenario.

Correct Answer: B

Rationale: The correct answer is B. Most umbilical hernias in newborns resolve on their own by 3 to 5 years of age without the need for surgical intervention, unless complications arise. Surgery is not typically recommended for umbilical hernias in newborns due to the high rate of spontaneous resolution. Aggressive treatment is not necessary as umbilical hernias are typically benign and not associated with high mortality. Taping the abdomen is not recommended as it can cause skin irritation and does not speed up the resolution of the hernia.

Correct Answer: D

Rationale: Cimetidine is an H2 blocker that reduces stomach acid, helping manage GER. Holding the infant in the prone position is not recommended due to the risk of SIDS. Breastfeeding should not be discontinued unless advised by a physician. Elevating the head to 90 degrees is excessive.

Correct Answer: A

Rationale: The 'sunset sign,' characterized by downward-driven eyes, is most commonly associated with hydrocephalus. This condition causes increased intracranial pressure, leading to the eyes appearing to be forced downward. Meningitis (choice B) typically presents with symptoms such as fever, headache, and a stiff neck, but not the 'sunset sign.' Cerebral palsy (choice C) is a group of disorders affecting movement and muscle coordination, not directly related to the 'sunset sign.' Encephalitis (choice D) is inflammation of the brain, which can cause symptoms like fever, headache, and confusion, but not the specific downward eye gaze seen in the 'sunset sign.'