What are the three types of protective works?

The correct focus is on venting, trenching, and buttressing as the three types of protective works. Each of these plays a significant role in mitigating the risk associated with unexploded ordnance (UXO) and enhancing safety in response operations.

Venting involves the creation of pathways that allow gases to escape, which can be particularly important in scenarios involving ordnance that may produce harmful fumes or pressure buildup. This technique ensures that any dangerous buildup poses less of a risk to personnel and equipment.

Trenching refers to the excavation method used to create channels that can safely contain or divert explosives or hazardous materials, helping to protect both the environment and individuals in the vicinity. It establishes a containment area that limits the spread of potential threats.

Buttressing provides structural support to control the landscape and reinforce containment protocols. It primarily serves to stabilize the ground around potentially dangerous areas, which is crucial in ensuring that accidental detonations or disturbances do not escalate into larger incidents.

The other options, although they describe materials or methods that may have their utility in various contexts, do not specifically classify as the primary types of protective works recognized in UXO safety and mitigation practices.