The structural metal frame of a building can be used as the required equipment grounding conductor for AC equipment.
See answer and applicable Code reference
The correct answer is: b) False
Article 250 covers the general requirements for grounding and bonding of electrical installations. Part VII of this Article focuses on the methods of equipment grounding. As specifically noted in Sec. 250.136(A), "Electrical equipment secured to and in electrical contact with a metal rack or structure provided for its support and connected to an equipment grounding conductor by one of the means indicated in 250.134. The structural metal frame of a building shall not be used as the required equipment grounding conductor for ac equipment."