A nurse is assessing children experiencing regression. Which of the following children should the nurse be concerned about?

A. Regression in gross motor skills over an extended period is concerning because it may indicate an underlying neurological, muscular, or developmental disorder, such as cerebral palsy, muscular dystrophy, or neurodegenerative disease. Persistent regression, especially in a previously normally developing child, warrants immediate evaluation by a primary care provider or specialist. B. Temporary regression of toilet training in the context of stressful events like hospitalization or illness is considered normal, situational regression and typically resolves once the stressor is removed. This does not indicate underlying pathology. C. Short-term regression in areas such as sleep, appetite, or behavior after major environmental changes, like starting day care, is a common and temporary stress response in toddlers. It usually resolves with adjustment to the new routine. D. Temporary sleep disturbances due to environmental changes or stressors are common in infants and toddlers. This is expected behavior and typically resolves as the child adjusts to the new environment.