Olaf, a Citizen of Norway with No Trade or Business

Olaf, a citizen of Norway with no trade or business activities in the United States, sells at a gain 200 shares of MicroShift, Inc., a U.S. company. The sale takes place through Olaf's broker in Oslo. How is this gain treated for U.S. tax purposes?

A) It is foreign-source income subject to U.S. taxation.
B) It is foreign-source income not subject to U.S. taxation.
C) It is U.S.-source income subject to U.S. taxation.
D) It is U.S.-source income exempt from U.S. taxation.