The "materials balance" circular flow of economic activity is different than the conventional circular flow because the materials balance approach: O All of the available answers. Recognizes the need for flows of natural resources such as water and energy to support economic production and consumption. Includes the flow of ecosystem services from the environment that can provide direct benefits to households. Embodies the first law of thermodynamics that matter can neither be created nor destroyed. O Highlights the flow of byproducts (residuals) from firms and households to the environment. A common reason why it is difficult to resolve negative environmental externality problems through private bargaining as suggested by the Coase Theorem is: O Existing laws prevent private bargaining. O Large number of people are impacted by the externality and transactions costs are high. O Property rights already protect against negative externalities. O All of the available answers. O Environmental externality problems rarely exist in a market economy.