QUESTION 21 _refers to the benefit given up by choosing an alternative course of action. O Irrelevant cost . Relevant cost . Sunk cost OD. Opportunity cost QUESTION 20 in deciding whether to drop its electronics product line a company's manager should ignore OA the variable and fixed costs it could save by dropping the product line O B. the variable and fixed costs it could save by dropping the product line O the effect of dropping the electronics product line on the sales of its other products OD. the amount of unavoidable fixed costs