When must abandoned fiber optic cables be removed?

The correct answer emphasizes the approach of tagging abandoned fiber optic cables for future use rather than immediate removal. This practice is based on cost-effectiveness and the potential for repurposing existing infrastructure. Fiber optic cables can represent significant investment and, in some cases, may still be viable for future projects or expansions. Tagging allows for easy identification and tracking without the need for immediate removal, which can be labor-intensive and costly.

The idea behind this approach is that as technology evolves, the original cables may still hold some value for communication or network improvements, and tagging keeps them recognized and documented without disrupting current systems. Therefore, labeling them for possible future use is preferred over removing them outright.

In contrast, the other options suggest more immediate or absolute actions that may not always be necessary or practical. Removing all abandoned cables can be an unnecessary expenditure; damage doesn't always deem cables unusable; and limiting such actions to renovation can underestimate the need for proactive maintenance in network management.