检索选修四门以上课程的学生总成绩(不统计不及格的课程)，并要求按总成绩的降序排列出来。正确的SELECT语句是( )。

A．SELECT S#，SUM(GRADE)FROM SC
WHERE GRADE＞=60
GROUP 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．SELECT S#，SUM(GRADE) FROM SC
WHERE GRADE＞=60
ORDER BY2 DESC
GROUP BY S#
HAVING COUNT(*)＞=4