Do parts a, and b ( 10 points each) a. Identify the four types of market structures. What are the characteristics of the four types of market structure b. Draw the short-run ATC, AVC, MC, MR and Demand graphs for a perfectly competitive market experiencing a profit. In each part, show Total Cost (TC), Total Revenue (TR), shade the profit. Clearly label Q for the equilibrium quantity point and P for market price point.