Paragraph (1) shall not apply to stock treated as owned by a person by reason of section
1298
(a)(4) (relating to the treatment of a person that has an option to acquire stock as owning such stock) unless such person establishes that such stock is owned (within the meaning of section
958
(a)) by a United States shareholder (as defined in section
951
(b)) who is not exempt from tax under this chapter.