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，错误的是( )。

A．SELECT S.S#，SNAME FROM S WHERE S.S# =(SELECT SC.S# FROM SC WHERE C#='C2')

B．SELECT S.S#，SNAME FROM S，SC WHERE S.S#=SC.S# AND C#='C2')

C．SELECT S.S#，SNAME FROM S，SC WHERE S.S#=SC.S# AND C#='C2' ORDER BY S.S#

D．SELECT S.S#，SNAME FROM S WHERE S.S IN (SELECT SC.S# FROM SC WHERE C ＝'C2')