Where size 2 AWG THWN/THHN copper conductors, protected by a 100 ampere rated circuit breaker, are enclosed in a Schedule 40 PVC conduit to supply an air-conditioning unit, what is the MINIMUM size copper equipment grounding conductor required for this installation?

The Master Electrician exam in most electrical licensing examinations covers these topics: Grounding and bonding, Overcurrent protection, Wiring methods and installation, Boxes and fittings, Services and equipment, Motors, Special occupancies, Load calculations, Lighting, Appliances, Box and raceway fill, Hazardous locations, Trade knowledge and Electrical theory.