What concept evaluates outcomes when one player's best choice depends on the choices of others?

• A. Opportunity cost
• B. Game theory
• C. Marginal analysis
• D. Comparative advantage

Answer: (B)

The main concept here is game theory, which studies strategic decision-making when each player's best move depends on what others do. It looks at how people or firms choose actions by anticipating opponents' responses, often leading to outcomes like a Nash equilibrium where no one benefits from changing their strategy on their own. For example, two competing sellers deciding prices or a group deciding how to share a resource illustrate how one player's optimal choice hinges on the other’s likely move. The other options don’t capture this interdependence: opportunity cost focuses on what you sacrifice by choosing one option over another; marginal analysis weighs incremental costs and benefits of small changes; comparative advantage explains why entities specialize based on efficiency. So game theory best explains outcomes in such interdependent decision-making scenarios.