How many distinct colleges are associated with players from the team with name "Columbus Crew".
SELECT count(DISTINCT T1.College) FROM match_season AS T1 JOIN team AS T2 ON T1.Team  =  T2.Team_id WHERE T2.Name  =  "Columbus Crew"
distinct colleges = COUNT(DISTINCT College); associated with players = JOIN operation on team and player (or equivalent) tables; team with name 'Columbus Crew' refers to WHERE T2.Name = 'Columbus Crew';