Self-hosted runners can have default labels and custom labels. These labels are used in the runs-on field to route workflow jobs to runners that match the required criteria. When multiple labels are specified, the runner must match all listed labels before GitHub Actions can assign the job to that runner. Therefore, option A is correct. Option B is false because labels are especially important for self-hosted runners. Option C is incorrect because GitHub does not require the runner IP address as a routing label. Option D is also incorrect because workflows target runners by labels or runner groups, not by hostname. This topic validates runner selection, self-hosted runner configuration, and workflow job routing.