What is emphasized by Rule 4 regarding weapon handling?

Rule 4 emphasizes the importance of keeping the weapon on safe until you intend to fire. This practice is crucial for ensuring safety during handling and storage of firearms. The safety mechanism serves as a critical precaution that prevents accidental discharges and safeguards against unintentional harm. By maintaining the weapon's safety in the "on" position until an operator is ready to shoot, individuals reduce the risk of mishaps associated with handling loaded firearms. This is particularly important in environments where multiple handlers might be present or in scenarios where the individual may be distracted.

The other options, while they may pertain to general safety and maintenance, do not specifically address the immediate and critical nature of weapon readiness and safety protocols as highlighted in Rule 4. The primary focus of this rule is on the active safety of the weapon during periods of non-use, underscoring why maintaining the weapon in a safe mode is paramount until the decision is made to fire.