As used in this part, unless the context otherwise requires:
(1) “Disposition directions” means a legible written instrument signed by the decedent and acknowledged by a notary or witnessed by two (2) persons who are qualified adults; provided, that such written instrument may be, but is not limited to, a letter of instructions, a will, a trust document, or an advance directive;
(2) “Qualified adult” means a person who is eighteen (18) years of age or older and of sound mind; and
(3) “Right of disposition” means the right to determine the disposition of the remains of a decedent, including the location, manner, and conditions of disposition and arrangements for funeral goods and services.