The correct answer is D) the person performing the repair. The lock-out/tag-out procedure is a critical safety measure to ensure that electrical equipment is properly de-energized before any maintenance work is performed. This procedure must be carried out by the individual who is directly responsible for completing the repair or maintenance task, as they are the most familiar with the specific equipment and the work being done. The other options, such as the chief electrician, chief engineer, or watch engineer, may be involved in overseeing the work, but the actual lock-out/tag-out should be performed by the person doing the hands-on maintenance to ensure their personal safety and the safety of the equipment.