Refer to the Exhibit.

A DNS zone file is shown in the exhibit. The configuration for this domain is removed from the primary server, but the secondary server is not modified.

How long after the domain is removed from the primary server will the secondary server stop returning authoritative replies for this domain?

A.
immediately

B.
approximately 1 hour after

C.
approximately 10 days after

D.
approximately 15 minutes after

E.
approximately 30 minutes after