a. Would a foreign person be engaged in a domestic trade or business if the person owns stock in a foreign or domestic corporation that conducts a trade or business in the United States? Does the result depend upon the percentage of stock owned by such foreign persons?

b. Would a foreign person be engaged in a domestic trade or business if the person owns equity in a foreign or domestic partnership or limited liability company (rather than a corporation) that conducts a trade or business in the United States? Does the result depend upon the percentage of equity owned by such foreign person? What if such person is a limited partner?