Which of the following can be used to connect grounding conductors and bonding jumpers?

The correct answer is that any of these options can be used to connect grounding conductors and bonding jumpers. In electrical installations, grounding conductors and bonding jumpers are essential for safety, as they provide a path for fault currents and help prevent electric shock or fire hazards.

Grounding conductors can be made from a variety of materials, including copper and aluminum, both of which are commonly used in electrical work. Each material has its advantages; for instance, copper is known for its excellent conductivity and resistance to corrosion, while aluminum is lighter and often less expensive.

Additionally, while it is often recommended to use insulated conductors in certain situations to prevent corrosion and enhance safety, there is also a practice of using bare conductors for specific applications, as they can be effectively used for grounding without insulation.

Thus, since grounding and bonding can be achieved with copper, aluminum, or insulated conductors, the answer encompasses all materials and conditions that can effectively serve this purpose.