Following the conversion of an income trust to a unitrust, the trustee shall consider the unitrust amount as paid from the following sources, which are listed in order of priority:
(1) Net accounting income determined under this chapter as if the trust were not a unitrust;
(2) Ordinary income not allocable to net accounting income;
(3) Net realized short-term capital gains;
(4) Net realized long-term capital gains; and
(5) The principal of the trust.