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?

"The infant will always roll over once sleeping in a safety approved crib."

"He will learn to control his head first and then will learn to roll over. This is normal for his age."

"He is too young at this moment, so stop worrying."

"He will begin crawling before he can roll over"