问题详情

A．Select C#，AVG(Score)From学生成绩表 Group by score Order by 2，C# Desc
B．Select C#，AVG(Score)From学生成绩表 Group by C# Order by 2，C# Desc
C．Select C#，AVG(Score)From学生成绩表 Vyhere C# Desc Group by Score
D．Select C#，AVG(Score)From学生成绩表 Group by AVG(Score)Order by 2，C# Desc请帮忙给出正确答案和分析，谢谢！