Which method should Keisha use to send her e-mail announcements?

Keisha wants to use e-mail as a marketing tool. She suggests sending e-mail announcements to everyone on a mailing list, but her e-commerce administrator discourages this idea. Which method should Keisha use to send her e-mail announcements?

A.
Targeted e-mail

B.
Interoffice e-mail

C.
Spam e-mail

D.
Opt-in e-mail