针对学生选课表sc（sno, cno, grade），其中sno为学号，cno为课程号，grade为成绩。以下（ ）语句可查询选修了两门以上成绩在90分以上课程的学生学号。

A、select
sno from sc where
grade>90 group by sno having count(distinct sno)>2;
B、select
sno from sc where
grade>90 group by sno having count(cno)>2;
C、select
sno from sc where
grade>90
and
count(*)>2 group by sno;
D、select
sno from sc where
grade>90 group by sno having count(*)>2