MediaContact, Inc., specializes in sending spam on behalf of its clients. MediaContact may be required to do which of the following in order to comply with state laws? a. Solicit permission from all users to which it wishes to send commercial e-mail. b. Instruct spam recipients on how to "opt out" of their e-mails. c. Register with the state government as a "spam sender." d. Include the name and location of their corporate address in all e-mail transmissions.