2. Others.   Any of the following persons, in order of priority stated, when persons in prior classes are not available at the time of death, and in the absence of actual notice of contrary indications by the decedent, or actual notice of opposition by a member of the same or a prior class, may give all or any part of the decedent's body for any purposes specified in section 2903:

A.  The spouse;

A-1.  An agent designated by a durable health care power of attorney or an advance health-care directive under Title 18-A, Article 5, Part 8;

A-2.  A registered domestic partner, as defined in Title 22, section 2710;

B.  An adult son or daughter;

C.  Either parent;

D.  An adult brother or sister;

E.  A guardian of the person of the decedent at the time of his death; or

F.  Any other person authorized or under obligation to dispose of the body.