Four small real estate firms formed a cooperative advertising group to share the high cost of larger display advertisements that would draw more attention to

their listings. Calling their group "Sell$4$U$,"$ they began running a weekly half column. In addition to the names and numbers of all four firms, these

advertisements must clearly state

A$.$which firm has listed each of the properties advertised.

B$.$ that Sell$4$U is a cooperative group and not a national real estate franchise.

C$.$ whether all of the Sell$4$U real estate firms use the same commission structure.

D$.$that complaints must be directed to individual firms and not the Sell$4$U group.