【单选题】基于这样的三个表即学生表S、课程表C和学生选课表SC,它们的结构如下: S (S#,SN,SEX,AGE,DEPT) C (C#,CN) SC (S#,C#,GRADE) 其中:S#为学号,SN为姓名,SEX为性别,ACE为年龄,DEPT为系别,C#为课程号,CN为课程名,GRADE为成绩。 检索选修课程“C2”的学生中成绩最高的学生的学号。正确的SELECT 语句是( )。
A.
SELECT S# FROM SC WHERE C# =“C2”AND GRADE > = (SELECT GRADE FROM SC WHERE C# =“C2")
B.
SELECT S# FROM SC WHERE C# =“C2”AND GRADE IN (SELECT CRADE FROM SC WHEREC# =“C2")
C.
SELECT S# FROM SC WHERE C# =“C2”AND CRADE NOT IN (SELECT GRADE FROM SC WHERE C# =“C2")
D.
SELECT S# FROM SC WHERE C#=“C2” AND GRADE >= ALL (SELFCT CHRADE FROM SC WHERE C#=“C2")