A、MAN Clusters, because they would allow you to synchronously replicate state in low latency networks 

B、WAN Clusters, because they would allow you to asynchronously replicate state in nonlow latency networks.  

C、Transaction Log in the database, because you could avoid synchronizing two replication technologies (database and file)  

D、Data Guard, because it is the most effective way to replicate a state across locations

E、GoldenGate, because it is the most effective way to replicate a state across locations