produce myelin for the neurons in the central nervous system and produce myelin for nerves in the peripheral nervous system.

The correct options are
A Oligodendrocytes
C Schwann cells
Schwann cells, also called neurilemma cells, are cells in the peripheral nervous system that produce the myelin sheath around neuronal axons. The axons of the CNS get their myelin from oligodendrocytes in the CNS.
Astrocytes and neuron are other cells present in the brain.