Final answer:
The coorect answer is option c. To protect a trench 5-feet deep or more, trench boxes are the correct safety measure. They are specifically designed to prevent trench collapses and provide a secure work environment.
Step-by-step explanation:
When dealing with the safety measures required for trenches that are 5-feet or deeper, specific methods are mandated to protect workers from potential cave-ins and related dangers. To provide a correct answer to the question: "Which of the following can be used to protect a trench 5-feet or more in depth?", one must recognize what each of the listed options entails in terms of safety. While orange cones and traffic signs are useful for signaling and directing nearby traffic, and safety tape can mark boundaries, they don't offer structural protection against trench collapse.
Conversely, trench boxes, also known as trench shields or trench shoring systems, are specifically designed to protect workers within trenches. These robust structures are engineered to withstand the forces of the surrounding earth and create a safe work environment. Therefore, the correct option is (c) Trench boxes.