CompTIA A+ 220-801

Answer: D - All of the above are proper ESD prevention measures except leaving the system plugged-in to the wall outlet in order to provide outside grounding.

Key Takeaway: This myth has been floating around the tech community for years is even taught in some legitimate training programs; the idea is that since the computer is connected to the grounding wire in the wall (which in turn connects to the actual ground), there is a lower chance of ESD. In fact, by leaving the system plugged-in, you are creation a major danger to yourself-even if the power supply is switched to off, it could be faulty or worse, you could forget to turn it back off after testing something.