Final answer:
The one ongoing force supporting the group of international trade among the options provided is C. Globalization. It encourages economic integration globally, whereas protectionism restricts trade to protect domestic interests.
Step-by-step explanation:
The correct answer to the question "Which of the following is one of the four ongoing forces supporting the group of international trade?" is C. Globalization. Globalization refers to the process of interaction and integration among people, companies, and governments worldwide, and it's a driving force that supports and enhances international trade. This process has led to more interconnected economies and has increased the flow of goods, services, and capital across borders.
On the other hand, Protectionism is the economic policy of restraining trade between nations, which is often done through methods like tariffs, import quotas, and nontariff barriers. Such policies are usually intended to protect domestic industries from foreign competition. Therefore, protectionism is viewed as a force that can potentially undermine international trade rather than support it.