28) Tennill Inc. has a $1,400,000 investment opportunity with the following characteristics: Sales Contribution margin ratio Fixed expenses 4480,000 40 s 1,657,600 % of sales The ROI for this year's investment opportunity considered alone is closest to A)8.1% B) 128.0% C) 3.0% D) 9.6% 29) Which of the following costs are always irrelevant in decision making? A) avoidable costs B) sunk costs C) opportunity costs D) fixed costs be eliminated in whole or in part if a particular business segment is 30) Costs that can discontinued are called: A) sunk costs. B) opportunity costs C) avoidable costs. D) irrelevant costs