The synaptic knob of a neuromuscular junction is the portion of the muscle fiber that contains receptor sites for neurotransmitters.

Which of the following descriptions of glial cells is mismatched?

A) Microglia - provide support for the neuron cell body
B) Astrocytes - blood-brain barrier
C) Oligodendrocytes - form myelin sheaths
D) Ependymal cells - produce cerebrospinal fluid
E) Ependymal cells - choroid plexus