instruction: Find the club which has the largest number of members majoring in '600'.
response: SELECT t1.clubname FROM club AS t1 JOIN member_of_club AS t2 ON t1.clubid = t2.clubid JOIN student AS t3 ON t2.stuid = t3.stuid WHERE t3.major = "600" GROUP BY t1.clubname ORDER BY COUNT(*) DESC LIMIT 1