Users on a network report that they are receiving unsolicited emails from an email address that does not change. Which of the following steps should be taken to stop this from occurring?

A.
Configure a rule in each users router and restart the router.

B.
Configure rules on the users host and restart the host.

C.
Install an anti-spam filter on the domain mail servers and filter the email address.

D.
Install an ACL on the firewall to block traffic from the sender and filter the IP address.