Sec. 2. A power of attorney is valid if the power of attorney was valid at the time the power of attorney was executed under any of the following:
(1) This article.
(2) IC 30-2-11 (repealed).
(3) Common law.
(4) The law of another state or foreign country.
(5) The requirements for a military power of attorney under 10 U.S.C. 1044b.