Which market structure best describes (a) airplane manufacturing and (b) tomatoes? Why? Airplane manufacturing is A. monopolistically competitive because airplanes are a homogeneous product. B. an oligopoly because there are only a few large firms that are strategically interdependent. C. an oligopoly because there are many airline manufacturers. D. a monopoly because airplanes have no close substitutes. E. perfectly competitive because airline manufacturers are price takers. The market for tomatoes is A. an oligopoly because each tomato farmer produces a large share of the output. B. an oligopoly because tomato farmers have market power. C. monopolistically competitive because tomato farming has barriers to entry. D. a monopoly because tomatoes have no close substitutes. E. perfectly competitive because tomato farmers can easily enter and exit the market