设基于"学生-选课-课程"数据库中如下三个关系:S(Sno,SNAME,SEX,AGE), SC(Sno,Cno,GRADE), C(Cno,CNAME,TEACHER)。查询选修了课程号为'C2'的学生号和姓名,若用下列SQL的SELECT语句表达时,哪一个是错误的( )?
A.
SELECT S.Sno,SNAME FROM S WHERE S.Sno= (SELECT S
B.
SELECT S.Sno,SNAME FROM S,SC WHERE S.Sno = SSn
C.
SELECT S.Sno,SNAME FROM S,SC WHERE S.Sno = SSn
D.
SELECT S.Sno,SNAME FROM S WHERE S.Sno IN (SELECT