What commonly occurs to optical fibers and splices that are not protected in a splice closure?

Choosing the option that states optical fibers and splices that are not protected in a splice closure are susceptible to environmental damage is accurate because without proper protection, these components can be exposed to moisture, dirt, temperature fluctuations, and physical stress. Environmental factors can lead to performance degradation, which may cause signal loss, faults, or complete failure of the optical connection. Splice closures are specifically designed to shield fibers from these harmful elements, thus maintaining their integrity and ensuring optimal performance over time. This highlights the importance of protecting optical fibers and splices in various installation scenarios.