Final answer:
The exercise of Fiduciary Powers by national banks is primarily governed by 12 CFR 9, Fiduciary Activities of National Banks.
Step-by-step explanation:
The exercise of Fiduciary Powers by national banks is primarily governed by 12 CFR 9, Fiduciary Activities of National Banks. This regulation, issued by the Office of the Comptroller of the Currency (OCC), provides detailed guidance on the fiduciary activities that national banks can engage in. It covers topics such as qualifications for becoming a fiduciary, fiduciary powers and limitations, and reporting and record-keeping requirements. The regulation ensures that national banks comply with federal laws and regulations in their fiduciary activities.