(Consider This) 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

Costs that have already been incurred and cannot be recovered or refunded, and should not influence current or future decisions.

Variable Costs

Costs that change in proportion to the level of production or service activity.

Fixed Costs

Expenses that remain constant regardless of the amount of production, like lease payments or wages.