(a) A trustee shall allocate to income an amount received as a distribution of income from a trust or an estate in which the trust has an interest other than a purchased interest.
(b) A trustee shall allocate to principal an amount received as a distribution of principal from a trust or estate in which the trust has an interest other than a purchased interest.
(c) If a trustee purchases an interest in a trust that is an investment entity, or a decedent or donor transfers an interest in a trust that is an investment entity to a trustee, AS 13.38.600 or 13.38.750 applies to a receipt from the trust.