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