(d) The requirement is to identify the item that is not
one of the forces in Porter’s model for industry analysis. The
correct answer is (d) because consideration of general economic
conditions is not part of industry analysis. Answers (a), (b), and
(c) are incorrect because the five forces include the threat of new
entrants, the bargaining power of customers, the bargaining
power of suppliers, the threat of substitute products or services,
and the rivalry of the firms in the market.