how will AWS ensure that a switch from DB to a standby replica will not affect access to the application?

A user is accessing RDS from an application. The user has enabled the Multi AZ feature with the MS SQL RDS
DB. During a planned outage how will AWS ensure that a switch from DB to a standby replica will not affect
access to the application?

A.
RDS will have an internal IP which will redirect all requests to the new DB

B.
RDS uses DNS to switch over to stand by replica for seamless transition

C.
The switch over changes Hardware so RDS does not need to worry about access

D.
RDS will have both the DBs running independently and the user has to manually switch over

Explanation:

In the event of a planned or unplanned outage of a DB instance, Amazon RDS automatically switches to a
standby replica in another Availability Zone if the user has enabled Multi AZ. The automatic failover
mechanism simply changes the DNS record of the DB instance to point to the standby DB instance. As a result,
the user will need to re-establish any existing connections to the DB instance. However, as the DNS is the
same, the application can access DB seamlessly.