Who directed the show with the production code k2708?
CREATE TABLE "season_4_1998" (
  "series_num" real,
  "season_num" real,
  "title" text,
  "directed_by" text,
  "original_air_date" text,
  "production_code" text
);
SELECT "directed_by" FROM "season_4_1998" WHERE "production_code"='k2708';