A nurse is collecting data from an infant at a well-child visit. The nurse should understand that birth weight typically doubles by what age?

A. Birth weight typically triples by 12 months, not doubles. B. Birth weight typically doubles by 6 months, not 9 months. C. Birth weight does not double by 3 months, but by 6 months. D. Birth weight typically doubles by 6 months of age. This is a key developmental milestone in infancy.