Joshua and Ryzard Buy the Same Pair of Flip Flops

Multiple Choice

Joshua and Ryzard buy the same pair of flip flops, but each in the wrong size. Joshua proposes a size swap with Ryzard. This is an example of

A) barter, since the flip flops in the correct size represent a medium of exchange.
B) barter, since the flip flops in the correct size have intrinsic value to both Joshua and Ryzard.
C) money, since the flip flops in the correct size do not have any intrinsic value.
D) money, since the flip flops in the correct size represent a medium of exchange.