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。
选项：

A:select sno from scwhere grade>90group by snohaving count(cno)>2;
B:select sno from scwhere grade>90group by snohaving count( distinct sno)>2;
C:select sno from scwhere grade>90group by snohaving count(*)>2;
D:select sno from scwhere grade>90 and count(*)>2group by sno