Which of the following are policies applied to discount promotions？（）

A.If multiple discounts could apply to a given product/item， the promotion with the highest priority will be chosen.
B.If multiple discounts could apply to a given product/item， the promotion with the largest amount off will be chosen.
C.If more than one order level discount could apply to an order， the discount with the highest priority will bechosen.
D.If more than one order level discount could apply to an order， the discount with the largest amount off will be chosen.
E.If discounted shipping and another type of order level discount could apply to the same order， both are applied.