Which of the following describes a trench box's requirement in relation to a pipe?

A trench box, also known as a trench shield, is a critical piece of safety equipment used in excavation work to protect workers while installing utilities, including pipes. The requirement for a trench box to be centered over the pipe ensures that the trench shield provides adequate support and protection from soil collapse on all sides.

When a trench box is centered over the pipe, it creates a stable and safe working environment, allowing workers to operate without the constant risk of cave-ins, which can occur in unprotected excavations. This configuration also allows for proper installation, inspection, and maintenance of the pipe being laid.

The other options, such as installing the trench box underneath the pipe or away from the pipe, would not provide the necessary protective coverage and could lead to unsafe working conditions. Similarly, while offsetting the trench box from the pipe may offer some space, it would not ensure the same level of safety and stability as positioning it directly over the pipe does. This central positioning is crucial in meeting safety standards and mitigating risks to workers in excavation sites.