Which of the following is a main type of transport used in international logistics?

Air transportation is a main type of transport used in international logistics due to its speed and efficiency in moving goods across long distances. In a globalized economy, the ability to quickly ship time-sensitive products, perishables, or high-value items to international markets is essential. Airlines and freight carriers specialize in such logistics, ensuring that goods can be transported across continents in a matter of hours, compared to other modes of transport that may take days or weeks.

While other options like subway, cable car, and walking may have their places in local logistics or tourism, they do not serve the extensive needs of international trade. They are not utilized for large-scale shipping of goods across countries or between continents, which is the primary role of air transportation in the context of international logistics.