Which of the following is an example of a climbing facility?

Rungs and step bolts are specifically designed features that provide safe and reliable means for climbers to ascend and descend telecommunications towers. These components are essential for ensuring that technicians can perform their duties at height while maintaining stability and security. Rungs and step bolts are typically installed at regular intervals along the vertical structure of the tower, allowing for easy access and improving the overall safety of tower climbing.

In contrast, anchors are devices used for stabilization and securing equipment but do not facilitate climbing. Guy wires serve to support and stabilize the tower structure but are not used as climbing aids. Pull-up bars, while related to exercise, are not part of the climbing infrastructure of telecommunications towers and do not provide a functional means for climbing or working at height. This context highlights the specialized nature of the climbing facilities present in telecommunications towers, making rungs and step bolts the correct answer.