Past costs that are not affected by new decisions are known as

A) variable costs.
B) fixed costs.
C) marginal costs.
D) sunk costs.

Sunk Costs

Sunk costs are past expenditures that have already been incurred and cannot be recovered, and thus should not impact future decision-making.

Past Costs

Refers to expenses that have already occurred and cannot be recovered.

Marginal Costs

The supplementary cost that comes with producing an extra unit of a good or service.