Which of the Following Nonmonetary Exchange Transactions Represents a Culmination

Which of the following nonmonetary exchange transactions represents a culmination of the earning process?

A) Exchange of assets with no difference in future cash flows.
B) Exchange of products by companies in the same line of business with no difference in future cash flows.
C) Exchange of assets with a difference in future cash flows..
D) Exchange of an equivalent interest in similar productive assets that causes the companies involved to remain in essentially the same economic position.