Final answer:
Personnel should take cover about 6 feet (or about 2 meters) behind an M18A1 mine when firing it.
Step-by-step explanation:
When firing an M18A1 mine, personnel should take cover about 6 feet (or about 2 meters) behind the mine to ensure their safety.
Firing the mine creates a blast and debris that can be dangerous to anyone nearby. Taking cover at a safe distance helps protect personnel from the blast and flying fragments.
It is important to follow proper safety procedures and guidelines when handling and using explosive devices like the M18A1 mine to prevent accidents and injuries.
The correct answer is option safe distance for personnel to take cover before they fire an M18A1 mine or any explosive device is not directly provided in the referenced text.
The provided references discuss various situations related to weaponry and protection, including the operation of a Maxim gun, methods to protect oneself from blasts resulting from atomic weapons, the use of metal detectors to locate explosives, and historical context for firearms.
However, to answer the student's question properly, the U.S. Army's field manuals or other official military guidelines should be reviewed to obtain the exact safety distance recommended when employing an M18A1 mine or similar ordnance.