Which of the following statements about costs is NOT correct?

An avoidable cost is a cost that can be eliminated, in whole or in part, by choosing one chooses one alternative over another.

Allocated joint costs that occurred before the split-off point are relevant in the decision of whether to sell a product at the split-off point or to process the product further.

Avoidable fixed manufacturing overhead is relevant in a decision about whether a product line should be dropped.

Sunk costs are not relevant in decision making.