Which two data center design steps must be used to meet these requirements?

A cloud service provider provisioned four active/active data centers in various locations within the country at 50 miles between each data center. The data centers must provide redundant network infrastructure and always be available to customers.

Which two data center design steps must be used to meet these requirements? (Choose two)
A . Provide application hosting services to customers from the closest data center.
B . Implement active cluster in data centers 1 and 2 and backup in 3 and 4.
C . Use asynchronous replication between data centers 1 and 2.
D . Deploy database services in data center 1 and application layer to other data centers.
E . Configure application data replication to all backup data centers.

Answer: A,E