Which of the following statements are true? 1.Differential costs can only be variable 2.The potential benefit that is given up when one alternative is selected over another is called a sunk cost 3.The amount that a manufacturing company could eam by renting unused portions of its warehouse is an example of an opportunity cost 252) 1) Only statement is true 2) Only statement is true. 3) Only statement is true 4) All statements are true