如表10.3、表10.4、表10.5和表10.6所示,用SQL语言实现下列操作。列出各门课的平均成绩、最高成绩、最低成绩和选课人数。正确的SQL语句是_____ 。
A.SELECT 课号,AVG(成绩),MAX(成绩),MIN(成绩),COUNT(学号) FROM 选课GROUP BY 课号
B.SELECT 课号,AVG(成绩),MAX(成绩),MIN(成绩),COUNT(学号) FROM 选课ORDER BY 课号
C.SELECT 课号,AVG(成绩),MAX(成绩),MIN(成绩),COUNT(学号) FROM 选课WHERE 课号
D.SELECT 课号,AVG(成绩),MAX(成绩),MIN(成绩),COUNT(学号) FROM 选课HAVING 课号