Which one of the following descriptions about counter-offer is correct?

、Counter-offers are made to show the seller’s disagreement to the price, packing, quantity or the date of delivery and state his own terms instead.
B、If the buyer finds any terms or conditions in the offer unacceptable, he can negotiate with the seller and make counter-offers.
C、The buyer can’t make a counter-offer to a firm offer, because it is final.
D、While making a counter-offer, the buyer either accept all the terms in the offer or refuse all the terms in the offer.