单选题

找出符合条件的sql

Question

数据库中存在学生表S、课程表C和学生选课表SC三个表，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。请检索选修课程号为C2的学生中成绩最高的学号。( )

A. SELECT S#，SUM(GRADE)FROM SC WHERE GRADE＞=60 GROUP BY S# ORDER BY 2 DESC HAVING COUNT(*)＞＝4 WHERE C#=&ldquoC2&rdquo AND GRADE ＞=(SELECT GRADE FORM SC WHERE C#=&ldquoC2&rdquo)

B. SELECT S# FORM SC WHERE C#=&ldquoC2&rdquo AND GRADE IN (SELECT GRADE FORM SC WHERE C#=&ldquoC2&rdquo)

C. SELECT S# FORM SC WHERE C#=&ldquoC2&rdquo AND GRADE NOT IN (SELECT GRADE FORM SC WHERE C#=&ldquoC2&rdquo)

D. SELECT S# FORM SC WHERE C#=&ldquoC2&rdquo AND GRADE＞＝ALL (SELECT GRADE FORM SC WHERE C#=&ldquoC2&rdquo)