The C option indicates 2 ways that don't help with staying safe around eletricity. A ground fault interrupter will not effectively protect you from possible incidents with eletricity, as it only works if there is a short circuit or a really big amount of energy going through that point. Inspecting the extension cords needs to be done constantly, or there can be abrasions or cuts that won't be noticed. Even though portable tools don't pose much of a threat, as they usually aren't the cause of shocks, they don't help you avoid them.
