(c) A tax required to be paid by a trustee on the trust's share of an entity's taxable income must be paid:
- (1) From income to the extent that receipts from the entity are allocated only to income;
- (2) From principal to the extent that receipts from the entity are allocated only to principal;
- (3) Proportionately from principal and income to the extent that receipts from the entity are allocated to both income and principal; and
- (4) From principal to the extent that the tax exceeds the total receipts from the entity.