To manage the operations of all North American Business Units in Marketing Cloud, including Email Studio, Mobile Connect, and Social Studio, the two roles suitable for the new hire are:

C. Marketing Cloud Regional or Local Administrator: This role provides administrative capabilities specific to regional operations, suitable for managing multiple business units within a geographic area.

D. Marketing Cloud Administrator: This standard role provides full administrative rights across the entire Marketing Cloud environment, ideal for overseeing operations across various channels and business units.

These roles ensure the new hire has the necessary permissions to effectively manage and oversee the various platforms and business units within North America.