; (B) administer oaths or affirmations; or (C) compel the attendance of witnesses or the production of documentary and other evidence. (4) Actions by the commission In any case in which an action is instituted by or on behalf of the Commission for violation of this Act, no State may, during the pendency of that action, institute a separate action under paragraph (1) against any defendant named in the complaint in the action instituted by or on behalf of the Commission for that violation. (5) Venue; service of process (A) Venue Any action brought under paragraph (1) may be brought in— (i) the district court of the United States that meets applicable requirements relating to venue under section 1391 of title 28, United States Code; or (ii) a State court of competent jurisdiction. (B) Service of process In an action brought under paragraph (1) in a district court of the United States, process may be served wherever defendant— (i) is an inhabitant; or (ii) may be found.