A GFCI device trips when current leaving on the ungrounded conductor does not match current returning on the intended current path. What condition is it detecting?

1. AA ground-fault leakage path.
2. BAn overload condition where the load current is above the breaker rating.
3. CA line-to-neutral short circuit that must be cleared only by the GFCI sensor.
4. DNormal motor inrush current that is returning on the intended circuit conductors.