In terms of safety protocols, the first action upon discovering an explosive device should be to?

Securing the area immediately is crucial when an explosive device is discovered. This action ensures the safety of all personnel by preventing anyone from entering the potentially hazardous zone where the device is located. By effectively managing the perimeter, you reduce the risk of additional individuals being harmed and contain the situation to a controlled environment.

This primary action allows for a proper assessment of the situation to occur without further threat to life or limb. While confirming the device's threat level, evacuating personnel, and attempting to neutralize the device are also important steps, they should not be the immediate response. Without securing the area first, other actions may put personnel at unnecessary risk.