单项选择题

A.select部门,avg(成绩)from绩效成绩where员工id>1
B.select部门,avg(成绩)from绩效成绩group by部门having员工id>1
C.select部门,avg(成绩)from绩效成绩group by部门having count(员工id)>1
D.select部门,avg(成绩)from绩效成绩where count(员工id)>1 group by部门