有订单表orders,包含用户信息userid,产品信息productid,以下( )语句能够返回至少被订购过两回的productid?

A. select productid from orders where count (productid)>1
B. select productid from orders where max (productid)>1
C. select productid from orders where having count (productid)>1 group by productid
D. select productid from orders group by productid having count (productid) >1