15. Supporting cells in the Central Nervous System (CNS) that line the central cavities of the brain and spinal cord are called:T +' a) astrocytesT + b) oligodentrocytes + c) ependymal cellsT + d)...

please answer 15,16,17

Extracted text: 15. Supporting cells in the Central Nervous System (CNS) that line the central cavities of the brain and spinal cord are called:T +' a) astrocytesT + b) oligodentrocytes + c) ependymal cellsT + d) Schwann cells T 16. Supporting cells that produce myelin sheaths around nerve fibersT + a) are only found in the peripheral nervous system (PNS)T + c) are only found in the CNST + d) are only present during embryonic developmentT 17. Which of the following statements is/are true regarding neurons?T + a) Neurons have a high metabolic rate and require continuous glucose and oxygen. T + b) Neurons have a well-developed rough endoplasmic reticulum (ER) that stains heavily with basic dyes and is referred to as Nissl bodies. T + ) Neurons have only one axon but may have many dendrites. T + d) Clusters of neuron cell bodies are called nuclei when located in the CNS and ganglia when located in the PNS. T + e) All of the above (a, b, c and d) are correct. T