对于教学数据库的三个基本表：S(Sno,sname,Ssex),SC(Sno,cno,Grade),C(Cno,Cname,Teacher)，其中s表为学生表，SC为学生选课表，C为课程表，则对于语句：检索至少选修LIU老师所授课程中一门课程的女生姓名，SQL语句错误的是

A．SELECT Sname<br> FROM S,SC,C<br> WHERE S.Sno=SC.Sno AND SC.Cno=C.Cno AND Teacher='LIU'AND Ssex<br> ='F'
B．SELECT Sname<br> FROM S WHERE Ssex='F'AND Sno IN<br> (SELECT Sno<br> FROM SC<br> WHERE Cno IN(SELECT Cno FROM C<br> WHFRF Teacher='LIU'))
C．SELECT Sname<br> FROM S WHERE Ssex='F' AND EXISTS(SELECT*<br> FROM SC<br> WHERE SC.Sno=S.Sno AND EXISTS<br> (SELECT*<br> FROM C<br> WHERE Teacher='LIU'))
D．SELECT Sname<br> FROM S WHERE Ssex='F'AND EXISTS(SELECT*<br> FROM SC<br> WHERE SC.Sno=S.Sno AND EXISTS<br> (SELECT*<br> FROM C<br> WHERE C.Cno=SC.Cno AND<br> Teacher='LIU'))