Final answer:
The true statement about oligodendrocytes is that they form myelin sheaths within the central nervous system.
Step-by-step explanation:
Regarding oligodendrocytes, the true statement is that they form myelin sheaths within the central nervous system (CNS). Oligodendrocytes are a type of glial cell found in the CNS whose main function is to produce the myelin sheaths that insulate axons.
This myelin sheath facilitates the rapid and efficient transmission of electrical signals along the axon. On the other hand, the peripheral nervous system (PNS) has Schwann cells, which are responsible for myelinating axons in the PNS. Therefore, oligodendrocytes do not myelinate axons in the PNS.