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 BY S# D.SELECT S#,SNAME FROM S WHERE S# IN(SELECT SS# FORM SC WHERE C#=‘C2’)