Which of the following is NOT one of the four firearms safety rules?

The statement that assumes all guns are unloaded is indeed one of the fundamental firearms safety rules, so it does not answer the question correctly. The purpose of this safety rule is to promote a mindset of caution and responsibility when handling firearms. It encourages individuals to treat every gun as if it is loaded to prevent accidents.

The key safety rules include always treating a firearm with respect, being aware of what lies beyond the target, keeping fingers away from the trigger until ready to shoot, and ensuring that the muzzle is always pointed in a safe direction. Failing to remember any of these principles can lead to dangerous situations. In this context, understanding and internalizing these rules is essential for anyone trained in the use of firearms to ensure both personal safety and the safety of those around them.