I need the answer to this question:

Assume that the trade opens between Argentina and New Zealand and that, with trade, a pound of mutton exchanges for a bushel of wheat. Before trade, Argentina produced at point A and New Zealand produced at point C. Argentina moves to point B, while New Zealand moves to point D. Calculate and illustrate graphically an exchange between Argentina and New Zealand that would leave both countries with more of both goods than they had before trade.

The answers for this question skip this question.