Select a specific real-world firm or market and discuss which model of market structure you think would be most appropriate to describe that market.

(ie. Perfect competition, monopolistic competition, oligopoly, monopoly.)

Real world markets never exactly meet the assumptions of the models, so you can also talk about what aspects of the real-world market may not fit the model what aspects are not well described by the model selected.

You might want to consider, if relevant in your case, factors such as: the nature of the product, factors about the production such as whether or not there are likely to be economies of scale, the number of competitors, the degree of market power, how firms compete, and outcomes such as prices, mark ups, profits and firm entry/exit.