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,AGE 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 GRADE FROM SC WHERE C#="C2")
C.SELECT S# FROM SC WHERE C#="C2" AND GRADE NOT IN (SELECT GRADE FROM SC WHERE C#="C2")
D.SELECT S# FROM SC WHERE C#="C2" AND GRADE >= ALL (SELECT GRADE FROM SC WHERE C#="C2")