Answer:
The answer is d: physically on the U.S. soil but considered to be outside U.S. commerce.
Step-by-step explanation:
Foreign trade zones are areas within the United States or near a port of entry where foreign and domestic goods are deemed to be outside the U.S. trade. Tariffs and quotas are removed in foreign trade zones and new companies and foreign investments seem to be attracted by these areas, as the requirements for operating therein are not difficult to meet. These areas are under the U.S. Customs and Border Protection supervision.
The goods in foreign trade zones receive the same treatment by the US Customs as it were outside the commerce of the United States.