Unless otherwise provided by the governing instrument, determined by the trustee, or ordered by the court, distributions to beneficiaries shall be considered paid in the following order from the following sources:
(a) From net taxable income other than capital gains.
(b) From net realized short-term capital gains.
(c) From net realized long-term capital gains.
(d) From tax-exempt and other income.
(e) From principal of the trust.