True or False: Metal parts and equipment of signs must be bonded together and to the grounding conductor supplying the system.

The statement is true because in electrical systems, particularly in installations involving signs, it is crucial that metal parts and equipment are properly bonded together and to the grounding conductor. This bonding is essential for several reasons:

1. Safety: Proper bonding helps to ensure that in the event of a fault condition, any stray currents will be directed safely to the ground. This minimizes the risk of electric shock to individuals who may come into contact with the metal parts.

2. Equipment Protection: Bonding reduces the risk of equipment damage. If metal parts aren't bonded effectively, a fault can cause excessive voltage on these surfaces, potentially damaging the equipment or creating fire hazards.

3. Compliance with Code: Electrical codes, such as the National Electrical Code (NEC) in the United States, mandate bonding of metal enclosures and equipment. Compliance ensures that installations are safe and meet legal requirements.

In contrast, the other choices do not hold true in the context of electrical safety practices regarding bonding and grounding.