Which components are used to protect and isolate optical fibers in outside plant fiber-optic cable?

The correct choice highlights the critical components used in outside plant fiber-optic cables to ensure both protection and isolation of the optical fibers. Strength members are essential for providing tensile strength, allowing the cable to withstand forces that might otherwise damage the delicate fibers inside. These are usually made from materials like Kevlar or steel that can endure pulling and stress during installation and throughout the cable's life.

Buffer tubes play a vital role in protecting the optical fibers from environmental damages, such as moisture and physical abrasion. They also provide a mechanism for the fibers to expand and contract with changes in temperature and other conditions without risking breakage or damage. The combination of strength members and buffer tubes creates an effective system that maintains the integrity of the optical fibers, ensuring reliable performance over time.

The other options do not encompass the specific protective and isolating functions necessary for optical fibers in outdoor environments. For example, conduits and safety covers may offer some level of protection, but they are not intrinsic components of the cable itself. Insulating plates and splices are more related to the connections and terminations rather than direct protection. Sheathing and coatings do provide a level of environmental protection but do not specifically address the structural needs for fiber support in the way that strength members and buffer tubes do