Which one of these statements is an example of how trust and identity management solutions should be deployed in the enterprise campus network?

Which one of these statements is an example of how trust and identity management solutions should be deployed in the enterprise campus network?
A. Authentication validation should be deployed as close to the data center as possible.
B. Use the principle of top-down privilege, which means that each subject should have the privileges that are necessary to perform their defined tasks, as well as all the tasks for those roles below them.
C. Mixed ACL rules, using combinations of specific sources and destinations, should be applied as close to the source as possible.
D. For ease of management, practice defense in isolation – security mechanisms should be in place one time, in one place.