单选题 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')