Which of the Following Statements Is a Characteristic of Countertrade

Which of the following statements is a characteristic of countertrade?

A) It refers to a form of trade in which all or part of the payment for goods or services is in the form of other goods or services.
B) It refers to the sale of an exported product at a price lower than that charged for the same or a like product in the "home" market of the exporter.
C) It refers to the active ownership of a foreign company or of overseas manufacturing or marketing facilities.
D) It refers to a system in which prices of different currencies move up and down based on the demand for and the supply of each currency.