For safe electrical grounding, which of the following properties is vital for a grounding conductor?

The vital property for a grounding conductor is electrical conductivity. This characteristic ensures that the grounding conductor can effectively carry fault currents safely to the ground, reducing the risk of electric shock and equipment damage. A grounding system relies on its ability to provide a low-resistance path for electrical currents. High electrical conductivity in the conductor material plays a crucial role in achieving this necessary low resistance, allowing fault currents to dissipate quickly and reliably into the earth.

Other properties such as flexibility, corrosion resistance, and durability are important but do not directly impact the essential function of grounding conductors in the same critical way. While flexibility might aid in installation or compliance with bending requirements, and corrosion resistance contributes to the longevity and reliability of the grounding system, it is the electrical conductivity that primarily determines how effectively a grounding conductor will perform its crucial safety function.