选择一个对下列SQL语句描述正确的选项？ SELECT * FROM EMPLOYEES E JOIN DEPARTMENTS D ON (D.DEPARTMENT_ID=E.DEPARTMENT_ID) JOIN LOCATIONS L ON (L.LOCATION_ID =D.LOCATION_ID); A JOIN . . . ON子句用于多个表的连接 B 会产生笛卡尔积 C 关联3张表不允许 D 都不对