A.SELECT S#,SNAME FROM S WHERE S#=(SELECT SS# FROM SC WHERE C#=\’C2\’) B.SELECT S#,SNAME FROM S,SC WHERE S#=SS# AND C#=\’C2\’ C.SELECT S#,SNAME FROM S,SC WHERE S#=SS# AND C#=\’C2\’ORDER BYS# D.SELECT S#,SNAME FROM S WHERE S# IN(SELECT SS# FROM SC WHERE C#=\’C2\’)