Answer: d. Game theory is not necessary for understanding competitive or monopoly markets.
Step-by-step explanation:
Game Theory in Business is applied to see the options available to competitors in the market if they engage in certain actions because the outcome of one party's decision is affected by the decision of the other party. In the context of business it is often used to calculate how much profit or loss companies will make if they engage in certain actions based on the decisions of the other party.
It is therefore not necessary in Perfect Completions because the market sets the price and the participants follow. There is not need to analyse what will happen if one party picks a certain method and the other as well. It will be irrelevant because the same price will be imposed regardless.
It is also unnecessary in Monopoly markets simply because a monopoly has market control and Game theory is for situations where at least 2 parties are fighting for market control.