Question

when all the costs of production are paid by sellers and all the benefits are received by consumers, there are:
no profits.
maximum profits.
no externalities.
no shortages or surpluses.

Explanation:

Externalities occur when production costs fall on third parties (not sellers) or benefits go to third parties (not consumers). The scenario describes a market where all production costs are borne by sellers and all benefits accrue directly to consumers, meaning no external costs or benefits affect outside parties. The other options are incorrect: profits depend on revenue vs costs, not this cost/benefit alignment; shortages/surpluses relate to supply-demand equilibrium, not this specific condition.

Answer:

no externalities.