设数据库mydb中有3个表：
Student(Sno,Sname,Sage)
Course(Cno,Cname)
SC(Sno,Cno,Grade)
其中，Sno,Sname,Sage表示学生的学号、姓名、年龄，Cno、Cname表示课程的课程编号、课程名称，Grade表示成绩。
查询选修了至少3门课程的学生的学生表信息，正确的SQL语句是
Aselect * from Student,SC
where count(*) >= 3
group by Sno
Bselect Student.* from Student,SC
where count(*) >= 3
and Student.Sno = SC.Sno
group by Sno
Cselect Student.* from Student,SC
group by Sno
where count(*) >= 3
and Student.Sno = SC.Sno
Dselect * from Student
where Sno in (
select Sno from SC
group by Sno
having count(*) >= 3)