在SQL中，集合成员算术比较操作“元组＜＞ALL(集合)”中的“＜＞ALL”的等价操作符是 ______。

A．SELECT S#,SUM(GRADE)FROM SC
WHERE GRADE＞=60
CROUP BY S#
ORDER BY 2 DESC
HAVING COUNT(*)＞=4
B．SELECT S#,SUM(GRADE)FROM SC
WHERE GRADE＞=60
GROUP BY S#
HAVING COUNT(*)＞=4
ORDER BY 2 DESC
C．SELECT S#,SUM(GRADE)FROM SC
WHERE GRADE＞=60
HAVING COUNT(*)＞=4
GROUP BY S#
ORDER BY 2 DESC
D．DELECT S#,SUM(GRADＥ)FROM SC
WHERE GRADE＞=60
ORDER BY 2 DESC
CROUP BY S#
HAVING COUNT(*)＞=4

A．列表框和组合框都可以设置成多重选择
B．列表框可以设置成多重选择，而组合框不能
C．组合框可以设置成多重选择，而列表框不能
D．列表框和组合框都不能设置成多重选择