Which of the following best describes cross-border payments?

Payments between different countries using ACH best captures the essence of cross-border payments. Cross-border payments refer to transactions where money moves from one country's banking system to another, which can involve various methods such as electronic payments, wire transfers, and automated clearing house (ACH) transactions.

ACH can facilitate these international transfers by enabling electronic payments between different countries, thus making them a significant part of cross-border payment solutions. While ACH is commonly associated with domestic transactions in the U.S., it can also function in an international context, especially in regions where cross-border ACH networks exist.

The other options do not accurately describe cross-border payments. Payments limited to local transactions only do not involve multiple countries and therefore do not qualify as cross-border. Payments that happen exclusively in cash ignore the electronic means that dominate today's cross-border financial transactions. Lastly, stating that payments are conducted through credit cards only narrows the scope too much, as cross-border payments encompass a variety of methods beyond just credit card usage.