What is the proper tool to clear an obstruction from a firearm?

The proper tool to clear an obstruction from a firearm is a cleaning rod. A cleaning rod is specifically designed for this purpose, as it can be inserted into the barrel of the firearm to safely push out any obstructions, such as dirt, debris, or a lodged bullet. This tool allows the user to address the blockage without causing additional damage to the firearm, ensuring that it can be returned to safe and proper functioning.

The other tools mentioned do not serve this specific function effectively. A screwdriver is designed for turning screws and would not provide the necessary action to clear a barrel. A wrench is typically used for tightening or loosening nuts and bolts, and is not suitable for clearing obstructions in a firearm. A brush may be used for cleaning, but it does not have the capability to remove obstructions from within the barrel. Understanding the correct tool for clearing obstructions is crucial for safe firearm handling and maintenance.