Final answer:
Nuclear chain intrafusal muscle fibers are characterized by peripheral nuclei in a chain-like arrangement. They are specialized sensory organs within the muscle spindle that are involved in proprioception, unlike skeletal, smooth, and cardiac muscle fibers which have different structures and functions.
Step-by-step explanation:
The characteristics of nuclear chain intrafusal muscle fibers are best represented by the option b) Peripheral nuclei in a chain-like arrangement. These muscle fibers are located within the muscle spindle and play a crucial role in proprioception, which is the sense of the relative position of one's body parts and the strength of effort being employed in movement. Unlike the extrafusal muscle fibers which cause muscle contraction, intrafusal muscle fibers are specialized sensory organs that detect the amount and rate of change in length of a muscle. They are encapsulated in a spindle-shaped structure and have nuclei arranged in a line, akin to a chain, which is why they are called nuclear chain fibers.
In contrast to skeletal muscle which has prominent striations and nuclei on the periphery, smooth muscle cells which possess a single nucleus and lack visible striations, and cardiac muscle cells that exhibit striations and contain a single nucleus, nuclear chain intrafusal fibers are distinctive owing to their unique nuclear arrangement and sensory function.