Hiroshi is the system administrator at an organization that has offices spread across three locations, Boston, London, and Paris. The organization has an Active Directory domain, domainA.com, with two domain controllers in each location for the marketing business unit. The company expanded recently and added over $3000$ new users across these locations. Hiroshi notices that this surge in users is causing Internet congestion because of the Active Directory replication.

What is a cost$-$effective method of dealing with this issue?

a$.$ Hiroshi should create separate domains for each location to avoid the need for replication.

b$.$ Hiroshi should create site objects and specify timed intervals for replication using site link objects.

c$.$ Hiroshi should reduce the number of domain controllers to just one per physical location.

d$.$ Hiroshi should remove all domain controllers and have only one domain controller for the domain.