(1) Subject to subsections (2) and (3) of this section and unless barred by RCW 68.64.060 or 68.64.070, an anatomical gift of a decedent's body or part may be made by any member of the following classes of persons who is reasonably available, in the order of priority listed:

(a) An agent of the decedent at the time of death who could have made an anatomical gift under RCW 68.64.030(2) immediately before the decedent's death;

(b) The spouse, or domestic partner registered as required by state law, of the decedent;

(c) Adult children of the decedent;

(d) Parents of the decedent;

(e) Adult siblings of the decedent;

(f) Adult grandchildren of the decedent;

(g) Grandparents of the decedent;

(h) The persons who were acting as the guardians of the person of the decedent at the time of death; and

(i) Any other person having the authority under applicable law to dispose of the decedent's body.

(2) If there is more than one member of a class listed in subsection (1)(a), (c), (d), (e), (f), (g), or (h) of this section entitled to make an anatomical gift, an anatomical gift may be made by a member of the class unless that member or a person to which the gift may pass under RCW 68.64.100 knows of an objection by another member of the class. If an objection is known, the gift may be made only by a majority of the members of the class who are reasonably available.

(3) A person may not make an anatomical gift if, at the time of the decedent's death, a person in a prior class under subsection (1) of this section is reasonably available to make or to object to the making of an anatomical gift.