(a) This section shall apply only in actions brought by, on behalf of, or for the benefit of those individuals specified in paragraphs (1) to (3), inclusive, to redress unfair or deceptive acts or practices or unfair methods of competition. (1) Senior citizens, as defined in subdivision (f) of Section 1761. (2) Disabled persons, as defined in subdivision (g) of Section 1761. (3) Veterans, as defined in Section 18540.4 of the Government Code. (b) Whenever a trier of fact is authorized by a statute