Which of the following statements correctly describes white matter and gray matter?

A) Gray matter in the brain and spinal cord is a concentration of myelinated axons and white matter in the brain and spinal cord is a concentration of dendrites.
B) White matter in the brain and spinal cord is a concentration of unmyelinated axons and gray matter in the brain and spinal cord is a concentration of dendrites.
C) White matter in the brain and spinal cord is a concentration of myelinated axons and gray matter in the brain and spinal cord is a concentration of myelinated dendrites.
D) White matter in the brain and spinal cord is a concentration of myelinated axons and gray matter in the brain and spinal cord is a concentration of dendrites.