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
Which club has the most members majoring in '600'?
CREATE TABLE student (
    stuid VARCHAR,
    major VARCHAR
)

CREATE TABLE member_of_club (
    clubid VARCHAR,
    stuid VARCHAR
)

CREATE TABLE club (
    clubname VARCHAR,
    clubid VARCHAR
)