3、在Oracle中，以下是STUDENTS表的结构： SID NUMBER NOT NULL，Primary Key SNAME VARCHAR2(30) COURSE_ID VARCHAR2(10) NOT NULL MARKS NUMBER 你需要查询参加了课程ID为C10的考试，并且分数排在前10名的学生，以下（ ）语句能够实现此功能。SELECT SID,marks,ROWNUM "Rank" FORM students

A. WHERE ROWNUM<=10 AND course_id='C10' ORDER BY marks DESC;SELECT SID,marks,ROWNUM"Rank" FORM students

B. WHERE ROWNUM<=10 AND course_id='C10' ORDER BY marks;SELECT SID,marks,ROWNUM"Rank" FORM (SELECT SID ,marks FORM students

C. WHERE ROWNUM<=10 AND course_id='C10') ORDER BY marks DESC;SELECT SID,marks,ROWNUM"Rank" FORM (SELECT SID ,marks FORM students

D. WHERE course_id='C10' ORDER BY marks DESC) WHERE ROWNUM<=10;