Eight-Year-Old Ella Can Use Scissors to Cut Small Paper Dolls

Multiple Choice

Eight-year-old Ella can use scissors to cut small paper dolls out of construction paper,something she could not do at age 3.What best accounts for her improving dexterity?

A) Increased cortical thickening in the temporal lobe.
B) Increased myelination of the central nervous system.
C) Increased bone ossification.
D) Increased muscle development.