A)the CNS to the effectors.
B)the CNS to the sensory receptors.
C)the effectors to the CNS.
D)the sensory receptors.to the CNS.

A)always interneurons.
B)sensory neurons other than the ones for the senses of hearing, equilibrium, vision, and smell.
C)always motor neurons.
D)sensory neurons for the senses of hearing, equilibrium, vision, and smell.
E)either motor neurons or interneurons.

A)Microglial cells
B)Ependymal cells
C)Oligodendrocytes
D)Astrocytes
E)Schwann cells