Which of the following conditions will cause a ground fault circuit interrupter (GFCI) to disconnect AC power?

A Ground Fault Circuit Interrupter (GFCI) is designed to protect people from severe electrical shocks. It works by constantly monitoring the current flowing out on the hot wire and the current returning on the neutral wire. Under normal, safe conditions, these two currents are exactly equal. If the GFCI detects an imbalance, it means some of the current is escaping through an unintended path to ground—such as through a person's body or a faulty metal chassis. This is known as a 'ground fault.' The GFCI will trip and disconnect the power almost instantly when it senses this leaked current. It does not trip due to overvoltage, nor does it trip for current flowing normally from hot to neutral, as that is just regular circuit operation.