Choice A rationale:

Lethargy and muscle weakness are common signs of electrolyte imbalances in a dehydrated child.

Dehydration can lead to an imbalance of electrolytes, such as sodium and potassium, which affects muscle function and overall energy levels.

Choice B rationale:

Increased appetite and hyperactivity are not typical signs of electrolyte imbalances in a dehydrated child.

Dehydration often leads to a decreased appetite and lethargy.

Choice C rationale:

Shortness of breath and coughing are not directly related to electrolyte imbalances in a dehydrated child.

These symptoms are more likely to be associated with respiratory or pulmonary issues rather than dehydration.

Choice D rationale:

Excessive thirst and urination are common signs of dehydration but are not indicative of electrolyte imbalances.

These symptoms occur as the body attempts to compensate for fluid loss by increasing thirst and increasing urine output.

Electrolyte imbalances are more likely to manifest as muscle weakness and cardiac arrhythmias.