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
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
HAVINC 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#
HAVINC COUNT(*) >=4