What Is One Significant Reason for the Advances in Fine

What is one significant reason for the advances in fine motor skills in children 6 to 8 years old?

A) Children live long enough to get more practice with fine motor skills.
B) Children's cognitive development is increasing.
C) Children have more opportunity to model fine motor skill behaviour(s) from others and practice on a consistent basis.
D) The amount of myelin in the brain increases to protect, insulate, and surround the nerve cells, raising the speed at which electrical impulses travel between neurons.