How can you lock a layer in AutoCAD?

The method of locking a layer in AutoCAD through the Layer Properties Manager is a common practice among users for its straightforwardness. By right-clicking on the desired layer within this interface and selecting the "Lock" option, you effectively prevent any unintended modifications to the objects contained in that layer. This locking mechanism is crucial for organizing your drawings and maintaining control over which elements can be edited or interacted with while working on complex designs.

The other options may seem plausible but don't accurately describe how to lock a layer. The "L" shortcut does not correspond to locking a layer; instead, it's typically associated with other commands. The "LOCK" command does not exist as an individual command within AutoCAD, and the "PROTECT" command is not used in this context either. Each of these alternatives fails to provide the efficient and organized method of locking layers that the Layer Properties Manager offers, highlighting the selected option as the most effective answer for managing layer settings in AutoCAD.