; or (C) take such other action as may be provided by law. (3) Action of attorney general When a matter is referred to the Attorney General pursuant to paragraph (2), or whenever the Attorney General has reason to believe that the State is engaged in a pattern or practice of discrimination in violation of the provisions of this subsection, the Attorney General may bring a civil action in any appropriate United States district court for such relief as may be appropriate, including injunctive relief. 688. Drug and child support services and referrals (a) Drug testing and rehabilitation (1) In general Nothing in this subtitle shall be construed to prohibit a State from testing participants in programs, projects, or services carried out or provided under this subtitle for controlled substances. A State that conducts such testing shall inform the participants who test positive for any of such substances about the availability of treatment or rehabilitation services and refer such participants for appropriate treatment or rehabilitation services. (2) Administrative expenses Any funds provided under this subtitle expended for such testing shall be considered to be expended for administrative expenses and shall be subject to the limitation specified in section 679(b)(2). (3) Definition In this subsection, the term controlled substance has the meaning given the term in section 102 of the Controlled Substances Act ( 21 U.S.C. 802 ). (b) Child support services and referrals During each fiscal year for which an eligible entity receives a subgrant under section 679(a), such entity shall— (1) inform custodial parents in single-parent families that participate in programs, projects, or services carried out or provided under this subtitle about the availability of child support services