Under what lightning condition will all units cease fire and take cover?

The correct answer indicates that under lightning condition L-10, all units are required to cease fire and take cover. This specific condition signifies a heightened hazard due to the proximity and frequency of lightning strikes, necessitating an immediate and unified response from all personnel to ensure safety.

When lightning is at a L-10 level, it typically means that there are conditions present which pose a significant risk of a lightning strike, compelling units to halt all activities and seek shelter to prevent injury or fatality. This protocol is crucial for maintaining the safety of all individuals involved in activities that could be endangered by the threat of severe weather, particularly lightning.

The other lightning conditions listed, while they may indicate varying levels of risk, do not invoke the same immediate response to cease fire and take cover. Each level typically corresponds to differing degrees of risk assessment, but L-10 is specifically designated as the critical threshold for taking action.