How should the administrator ensure that all of the mailboxes are being archived?

A check of the archive reports shows that only half of the mailboxes are being archived successfully during the scheduled archiving run.

How should the administrator ensure that all of the mailboxes are being archived?
A . create a new system mailbox and assign it to the archiving task
B . increase the number of concurrent connections in the archiving task properties from five to ten
C . increase the number of items per pass from 1000 to 2000
D . increase the archiving schedule window for the mailbox archiving task

Answer: D