Assume that Joe is willing to produce another hamburger that costs $1 to make. Mary is hungry and is willing to buy a hamburger for $3. According to the No Cash on the Table Principle, Joe and Mary:

A.will only make a trade if Joe can get Mary to spend more than $3 for the hamburger.

B.will only make a trade if Mary can get Joe to charge less than $1 for the hamburger.

C.will never trade; they will look for better deals.

D.will make a trade.

正确答案：will make a trade.