16. a. A document of gift shall be valid if executed in accordance with:
(1) the provisions of this act;
(2) the laws of the state or country in which it is executed; or
(3) the laws of the state or country in which the person making the anatomical gift is domiciled, has a place of residence, or is a citizen at the time that the document of gift is executed.
b. The law of this State shall govern the interpretation of a valid document of gift to which the provisions of this act apply.
c. A person shall presume that a document of gift or amendment of an anatomical gift is valid unless the person knows that it was not validly executed or was revoked.