The following types of glial cells (supportive cells) are responsible for helping to synthesize myelin, the insulation of axons: in the central nervous system (CNS) and in the peripheral nervous system (PNS.)

Oligodendrocytes and schawn cells.

Explanation:

Oligodendrocytes are form of gilial cells that is found in the Central nervous system. Oligodendrocytes secrete Myelin sheath around the axon of nerve fibres. They provide support and insulation to the Central nervous system.

Schawn cells are types of gilial cells found in the peripheral nervous system. They are also called neurilimma. They produce myelin sheath around the axon of neurons. They support nerve regeneration .

the correct answer is b