A company has the following specifications describing the functions that the users Alice, Bob, Charlie and John perform:

User	Functions
Alice	read account of Customer A
Alice	read account of Customer B
Alice	create project New Investment
Alice	own application Invoice Management
Alice	own application Customer Account

Bob	read account of Customer A
Bob	read account of Customer B
Bob	write in project New Investment
Bob	use application Customer Account
Charlie	read account of Customer A
Charlie	read account of Customer B
Charlie	use application Invoice Management
Charlie	use application Customer Account
John	read account of Customer A
John	read account of Customer B
John	use application Customer Account

a) Define the set of subjects, objects, and rights, and build the Access Control Matrix for this company. b) Propose a RBAC (Role-Based Access Control) model with Role Hierarchy to specify the above access rights to improve maintainability.