A nurse is assessing the development of a 3 month old during a well child visit. The concerned mother questions why he hasn't rolled over yet. What is the best response from the nurse?

A. "The infant will always roll over once sleeping in a safety approved crib.": Rolling over is a developmental milestone related to neuromuscular maturation, not the sleep environment. While safe sleep practices are important for preventing injury and SIDS, they do not influence the sequence or timing of motor development milestones. B. "He will learn to control his head first and then will learn to roll over. This is normal for his age.": Development follows a cephalocaudal pattern, meaning infants gain head and neck control before progressing to trunk movements like rolling. At 3 months, head control is still developing, and rolling typically occurs around 4–6 months, making this response accurate and reassuring. C. "He is too young at this moment, so stop worrying.": Although the infant is within the normal developmental range, dismissing parental concerns without explanation does not provide education or reassurance. Parents benefit from understanding developmental sequences and expected timelines. D. "He will begin crawling before he can roll over": Crawling is a later milestone that requires more advanced coordination and strength. Rolling over is a prerequisite skill that develops earlier, so this statement reflects an incorrect sequence of motor development.