Afflicted with lackluster ratings this season, the WB (Ch. 20 locally) is going to make some wholesale schedule changes starting Sunday. The network's revised Sunday lineup will include a new drama, ``D.C.,'' from the creators of ``Law & Order'' at 8 p.m.; the returning ``Movie Stars,'' a mere ratings blip when it aired briefly last summer; and the viewer-less ``Zoe.'' ``Felicity'' moves April 5 from the Sunday night spot where it has been battered much of the season to Wednesdays at 9 p.m., replacing ``Roswell'' in the post-``Dawson's Creek'' slot. ``Roswell,'' a terrific series that has labored in the shadows of ``The West Wing'' the entire season, will get a shot at renewal by moving to Mondays at 9 p.m. behind the WB's highly rated ``7th Heaven.'' All of the series will air original episodes through May.