Answer:
D. Failover
Step-by-step explanation:
Failover is a feature of an enterprise RDBMS that allows one server to take over the processing work of another server in case of a failure. This is done by automatically switching to a standby server in the event that the main server becomes non-operational. This feature is used to ensure high availability and continuity of service for the database. It ensures that the database is available and accessible to users even in the event of a server failure.