A Security Engineer is working with the development team to design a supply chain application that stores sensitive inventory data in an Amazon S$3$ bucket. The application will use an AWS KMS customer master key $($CMK$)$ to encrypt the data on Amazon S$3.$ The inventory data on Amazon S$3$ will be shared of vendors. All vendors will use AWS principals from their own AWS accounts to access the data on Amazon S$3.$ The vendor list may change weekly, and the solution must support cross$-$account access.What is the MOST efficient way to manage access control for the KMS CMK$7?$