Hint: Nerve fibres can be myelinated as well as non-myelinated that depends on the presence of myelin sheath. The presence or absence of myelin sheath in nerve fibres determines the speed of impulse generation and transmission.
Complete answer: The basic working unit of the brain, which is specialized and is designed to transmit some information to the other cells. These cells are divided into three parts- cell body, an axon, and dendrites. The cell body is also known as soma that help in the synthesis of proteins for the axons, dendrites, and synaptic knobs that contains specialized organelles such as mitochondria, endoplasmic reticulum, golgi apparatus, secretory granules, polysomes, and ribosomes to provide energy. Nodes of ranvier are microscopic gaps found between myelinated axons. They help to speed up the propagation of action potentials along the axon via saltatory conduction. They are periodic gaps present on the axons of the neurons and are insulated by the myelin sheath and it helps in the rapid conduction of nerve impulses. In the peripheral nervous system, schwann cells synthesize myelin sheaths around the neuronal axons. The myelin sheath consists of myelin. The myelin sheath is made up of water-soluble ions and lipids. They help in maintaining and regeneration of axons of the neurons. Various neurotrophic factors help in the regulation of Schwann cells. When the nerve fibres do not have myelin sheath they are known as non-myelinated or non-medullated fibres and the one with myelin sheath is known as myelinated/medullated fibers. Non-medullated neurons are found in the autonomous nervous system
Hence, the correct option is (B)-Soma
Note: In vertebrates, the action potential travels along the myelin-coated axons which are regenerated at the nodes of Ranvier that lack myelination and are identified by the tight junctions between the axons and the glial cells. Specific proteins are enriched in this region of the nodes. Axon is the body of the neurons and helps in the synthesis of these proteins.