Your customer is planning for a maximum-availability architecture at their data center to address their planned downtime, unplanned downtime, and replication needs.

Consider these options:

- Instance, site recovery, and heterogeneous setup

- Inter-region and intra-region load balancing across replicated databases

- Fine-grained error investigation of incorrect results

- Integrated client and application failover

- Fastest and simplest database replication

Which four options would you recommend?