假设“订单”表中有订单号、职员号、客户号和金额字段，正确的 SQL 语句只能是______。
A． SELECT 职员号 FROM 订单 GROUP BY 职员号 HAVING COUNT(*)>3 AND AVG_金额>200
B．SELECT 职员号 FROM 订单 GROUP BY 职员号 HAVING COUNT(*)>3 AND AVG(金额)>200
C．SELECT 职员号 FROM 订单 GROUP BY 职员号 HAVING COUNT(*)>3 WHERE AVG(金额)>200
D．SELECT 职员号 FROM 订单 GROUP BY 职员号 WHERE COUNT(*)>3 AND AVG_金额>200