In this section, “marketing” does not include materials to educate or inform a retail customer about standard offer service, default gas commodity service, or customer choice. Except as provided in subsection (d) of this section, an electric company or a gas company may not recover through its rates any costs associated with marketing its services. An electric cooperative may recover through its rates any costs associated with marketing its services, including the costs associated with materials that educate or inform a retail customer about standard offer service or customer choice. The Commission may, by regulation, adopt criteria for reviewing marketing and other communication materials of an electric company or a gas company to determine whether the cost of the materials may be recovered through the company’s rates.