(a) Any person may petition an agency in writing for a declaratory ruling as to the applicability of any regulation of the agency or the authority of the agency to promulgate a particular regulation. The agency shall, within thirty days after receipt of such petition, issue a declaratory ruling thereon.
(b) After compliance with the provisions of paragraph (a) of this section, any person affected by the provisions of any regulation of an agency may petition the Circuit Court for a declaratory judgment and/or injunctive relief if it is alleged that the regulation or its threatened application interferes with or impairs, or threatens to interfere with or impair, the legal rights or privileges of the plaintiff or that the regulation exceeds the regulatory authority of the agency. The agency shall be made a party to the action.