Which type of cost will not change if a decision is implemented and is never relevant to that decision?

The correct answer is sunk costs because these are expenses that have already been incurred and cannot be recovered. When making decisions about the future, sunk costs should not influence the decision-making process since they are not relevant to any potential outcomes.

For instance, if a business has spent money on a project that is now failing, that investment is considered a sunk cost. Even though the money spent may cause emotional attachment or concern, it should not affect current or future financial decisions regarding that project, since those costs cannot be changed by any current or future actions.

Fixed costs, on the other hand, remain constant regardless of production levels or decisions in the short term, but they can still be relevant for decisions affecting future expenses. Variable costs change based on production levels and are relevant to decision-making and future operations. Opportunity costs represent the potential benefits that are lost when choosing one option over another, making them very relevant to decision-making processes.