Can someone help me explain???

Which of the following statements is false?

C. Sunk costs are not relevant to the firm's decisions after it has entered the market.

D. Sunk costs, although likely to be important in guiding the decisions of firms, are unlikely to be influential on market structure

B. Sunk costs are an important factor in determining entry into a market because sunk costs cannot be recouped.

A. Sunk costs are an important factor in determining entry into a market because these costs may be quite high.