以下（ ）语句可查询选修了三门以上成绩在80分以上课程的学生学号。
A、select sno
from sc
where grade>80
group by sno
having count(cno)>3
B、select sno
from sc
where grade>80
group by sno
having count(*)>3
C、select sno
from sc
where grade>80 and count(*)>3
group by sno
D、
select sno
from sc
where grade>80
group by sno
having count(sno)>3
