What does the statement "The Exchange Online mailbox will be available after migration" imply?
A) The user's Exchange Online mailbox is currently accessible and fully functional.
B) The user's mailbox data is being transferred to the Exchange Online environment, and the mailbox will be accessible once the migration process is complete.
C) The user's Exchange Online mailbox has been permanently removed and is not retrievable.
D) The migration has been canceled, and the user's mailbox will remain on the on-premises server indefinitely.