At what age do fontanelles typically close in infants?

Fontanelles are the soft spots on an infant's skull where the bones have not yet fused together. These areas allow for the growth of the brain and the skull during the early stages of life. The anterior fontanelle, which is the largest fontanelle located at the top of the head, typically closes between 18 to 24 months of age.

The timing of fontanelle closure is crucial for proper skull and brain development. By this age range, the majority of infants have undergone significant growth, and the bones of the skull begin to fuse, safeguarding the brain while allowing for continued development. The closure of fontanelles indicates that the infant's cranial development is progressing normally. The specified age range reflects the typical developmental timeline observed in infants, making it the best choice among the given options.

In contrast, the other options suggest later ages for fontanelle closure, which is less consistent with the normal developmental timeline for most infants.