Who is the primary sponsor for crew cheif Rick Ren's team?
CREATE TABLE "drivers_teams" (
  "team" text,
  "truck_s" text,
  "num" real,
  "driver_s" text,
  "primary_sponsor_s" text,
  "listed_owner_s" text,
  "crew_chief" text
);
SELECT "primary_sponsor_s" FROM "drivers_teams" WHERE "crew_chief"='Rick Ren';