Final answer:
A nerve describes a bundle of axons in the peripheral nervous system, which carries electrical impulses between the brain and spinal cord and the rest of the body.
Step-by-step explanation:
The term that describes a bundle of axons in the peripheral nervous system is d. nerve. A nerve is essentially a collection of neuron fibers (axons), bound together by connective tissue, that transmits electrical impulses to and from the brain and spinal cord to various parts of the body. This definition distinguishes nerves from other structures like the nucleus, which is a collection of neurons found in the brain, a ganglion, which refers to a structure containing a number of nerve cell bodies, typically linked by synapses, and a tract, which is a bundle of axons within the central nervous system.