Answer: Option (b) is the correct answer.
Step-by-step explanation:
When we are not using our tools or if we are changing accessories such as blades, bits, and cutters then we need to unplug our tools.
This is because if we do not unplug our tools while changing accessories then it might be possible that we get electrical shock.
Thus, we can conclude that when changing accessories such as blades then you will need to unplug your tools.