单选题 检索选修课为“C2”的学生中成绩最高的学生的学号。正确的SELECT语句是( )。
A．SELECTS#FROMSC
WHERE C#="C2"AND GRADE>=
(SELECT GRADE FROM SC
WHERE C#="C2")
B．SELECTS#FROM SC
WHERE C#="C2" AND GRADE IN
(SELECT GRADE FROM SC
WHELRE C#="C2")
C．SELECT S# FROM SC
WHERE C#="C2" AND GRADE NOT IN
(SELECT‘GRADE FROM SC
WHERE C#="C2")
D．SELECT’S#FR()M SC
WHERE C#="C2" AND GRADE>=ALL
(SELECT’GRADE FROM SC
WHERE C#="C2")