If you cannot loosen the drill chuck by hand to remove the drill bit, you should use a...

The drill chuck is the part of the drill that holds the drill bit in place. When the drill bit is tightly secured and cannot be loosened by hand, a chuck key is the appropriate tool to use. A chuck key is specifically designed to fit into the holes or notches on the drill chuck to provide extra leverage and torque, allowing you to easily tighten or loosen the chuck.

Using a chuck key helps prevent damage to the drill or the drill bit that might occur if attempting to forcefully remove the bit by hand. It's essential to ensure that you are using the right tool for the task at hand, and in this case, the chuck key is the right choice for loosening a stubborn drill chuck.

Other options, while useful in different contexts, do not serve the purpose of removing a drill bit from a chuck effectively. For instance, a spanner wrench is typically used for turning nuts and bolts, and a torque wrench is for exerting a specific torque on a fastener. A drill bit holder helps in securely holding a bit in a different manner but is not used for loosening the chuck itself. The chuck key is specifically designed for this task, making it the best choice.