Which of the following MOST likely caused this?

A newly created user, john, reports that he has access to the file ?var/mail/joe? but should not have this access. Which of the following MOST likely caused this?

A.
User john was created with the same UID (User ID) as the removed user named joe.

B.
User john and joe are sharing a home directory.

C.
User john is forwarding all of his mail to joe.

D.
User joe’s email is still cached by the system although his UID (User ID) has been removed.