Which of the following is an example of countertrade?

Countertrade refers to transactions where goods or services are exchanged for other goods or services rather than using money. The first option aligns perfectly with this definition, as it explicitly states the act of buying a product without the use of currency, thereby showcasing the essence of countertrade.

The other choices do not fulfill the criteria for countertrade. Investing in foreign businesses involves financial transactions and is not an exchange of goods or services. Offering discounts for international shipping pertains to pricing strategies rather than a trade of goods without currency. Exporting products at standard prices also involves monetary transactions, which excludes it from the definition of countertrade. Thus, the first option correctly illustrates the concept of countertrade.