The right option is; a. axon
The axon is a thin fiber that carries signals away from the cell body.
The axon is a long slender projection of a nerve cell which conducts nerve impulses away from the body of the cell. The major role of the axon is to transfer information to different nerve cells, glands and muscles. Axons are divided into three types; groups A, B and C nerve fibers. Groups A and B are enclosed in a myelin sheath, while group C are not enclosed in a myelin sheath.