Which one of the following decisions most clearly reflects a good economic understanding of how to make decisions in the presence of sunk costs?
a) Continuing to invest in a failing project because a significant amount of money has already been spent on it
b) Abandoning a project that is not performing well and reallocating resources to more profitable ventures
c) Increasing spending on marketing efforts for a product that has already incurred substantial losses
d) Lowering the price of a product below cost in an attempt to recover initial investments