Which statement on incremental earnings is false?

a.

The total earnings from a new version of your product should be counted as incremental earnings.

b.

Incremental earnings are the total earnings resulting from a project.

c.

Sunk costs represent costs that we already made and should not be included for the calculation of incremental earnings even when the costs still need to be paid.

d.

Project externalities should be included when calculating the incremental earnings.