Which of the following would not generally be subject to federal estate and gift taxes?

Question 14 options:

An alien who is physically present in the U.S. at the time of his death

A person who is not a citizen, nor a resident, of the U.S. but owns stock issued by a U.S. corporation

A U.S. citizen not residing in the U.S.

An alien who is "domiciled" in the U.S.