Worksheet - Post Ramadan 1 Q1. Returns to scale shows the relationship between long-run average cost and output of a firm. Economies of scale arises when: A. long-run average cost decreases as output increases B. long-run average cost remains constant as output increases C. long run average cost rises as output rises D. None of the aboveQ2. The following are characteristics of an oligopoly market, except: A. Interdependence of firms B. High concentration ratio C. Easy to enter or leave the industry D. Product differentiation and price setters