What is the Season with an Acquisition via of rookie draft, and the number is 15?
CREATE TABLE "m" (
  "name" text,
  "position" text,
  "number" text,
  "school_club_team" text,
  "season" text,
  "acquisition_via" text
);
SELECT "season" FROM "m" WHERE "acquisition_via"='rookie draft' AND "number"='15';