The correct answer is B) commodity.
Mario paid three bushels of rice for three boxes of wool at the market. The type of money that Mario used for this exchange was a commodity.
The commodity is a product that has a value that can be used as "money" when there is no cash. The value of the product matches the value of other product and exchange can be completed.
The other options of the question are A) fiat, C) representative, and D) goods