Which of the following best describes a loose-tube fiber-optic cable?

A loose-tube fiber-optic cable is characterized by its design that permits the movement of fibers within a protective tube. This design is essential for several reasons, including the ability to accommodate temperature fluctuations and mechanical stress that can occur in various environments. The loose-tube construction allows the fibers to move freely without being constrained, which helps to minimize stress on the fibers that might result from temperature changes, expansion, or contraction of the cable materials.

This flexibility is crucial for maintaining the integrity and performance of the optical fibers over time, making these cables suitable for a variety of installations, including both indoor and outdoor settings where such environmental factors are a concern. The ability of the fibers to move slightly helps to prevent breakage or signal degradation that could occur in a more rigid cable design.

While other options touch on aspects of fiber-optic cables, they do not accurately represent the defining characteristic of loose-tube cables, which is the allowance for fiber movement to mitigate stressors associated with environmental changes.