The schwann cell forms a myelin sheath around the

The correct answer is D. Axon.

A Schwann cell is a type of glial cell that forms a myelin sheath around the axon of a neuron. The myelin sheath is a lipid-rich membrane that insulates the axon and helps to speed up the transmission of nerve impulses.

Dendrites are the branched projections of a neuron that receive signals from other neurons. The nucleus is the control center of the cell and contains the cell’s DNA.

Nodes of Ranvier are gaps in the myelin sheath that allow for the rapid transmission of nerve impulses.