(a) An amount received as interest, whether determined at a fixed, variable, or floating rate, on an obligation to pay money to the trustee, including an amount received as consideration for prepaying principal, must be allocated to income without any provision for amortization of premium.

(b) A trustee shall allocate to principal an amount received from the sale, redemption, or other disposition of an obligation to pay money to the trustee. The increment in value of a bond or other obligation for the payment of money bearing no stated interest but payable or redeemable at maturity or at a future time at an amount in excess of the amount in consideration of which it was issued is income. If the income accrues pursuant to a fixed schedule of appreciation, such income is distributable to the beneficiary at the time the increment occurs, and the trustee may transfer the amount thereof from principal to income on each such date. Whenever unrealized increment is distributed as income but out of principal the principal shall be reimbursed from the income when realized.

(c) This section does not apply to an obligation to which 11-A-4.9, 11-A-4.10, 11-A-4.11, 11-A-4.12, 11-A-4.14, or 11-A-4.15 applies.