Final answer:
U.S. exports of goods and services as a percentage of GDP are small compared to other industrialized countries due to the large domestic economy which supports a greater share of internal division of labor. Thus, the option "2" is the correct answer.
Step-by-step explanation:
The question relates to how the exports of goods and services of the United States compare in percentage terms to other industrialized countries. Given the information, it is clear that the United States has a smaller proportion of its economy dedicated to exports compared to many other industrialized nations. This phenomenon can be attributed to the fact that larger economies, such as the U.S., are able to sustain a greater share of their division of labor internally. Conversely, smaller economies like Belgium, Korea, and Canada engage more in international trade to reap the benefits of specialization, division of labor, and economies of scale.
Therefore, when we consider exports as a percentage of GDP, the exports of goods and services of the United States are small when compared to other industrialized countries. The U.S. economy's scale means it's less affected by globalization compared to smaller, more trade-dependent countries.