Dividends received from a domestic corporation are totally sourced to the U.S. if:

a. the corporation earns at least 80% of its gross income over the immediately preceding three tax years from the active conduct of a U.S. trade or business.

b. the corporation earns at least 25% of its gross income over the immediately preceding three tax years from the active conduct of a U.S. trade or business.

c. the corporation earns no more than 80% of its gross income over the immediately preceding three tax years from the active conduct of a foreign trade or business.

d. the corporation earns no more than 25% of its gross income over the immediately preceding three tax years from the active conduct of a foreign trade or business.

e. In all of the above cases.