Final answer:
The 'invisible hand' is a term describing how market forces guide economic activity to equilibrium without direct intervention, though some situations may require government action.
Step-by-step explanation:
The 'invisible hand' refers to the concept that market forces guide economic activity through the interactions of individuals and businesses each seeking their own self-interest. When markets are free of government intervention, these market forces tend to drive the economy toward equilibrium, where the supply of goods meets the demand. This trend towards equilibrium without the need for directed societal or governmental action represents the invisible hand in action. However, economists also acknowledge that government intervention may be necessary in certain cases, such as in monopolies or when dealing with negative externalities, and that the real-world application of the invisible hand requires an understanding of the strengths and weaknesses of both unregulated markets and government action.
To answer the student's question directly, b) market forces are what the invisible hand directs economic activity through. This concept is crucial in understanding how economists view the role of markets and government in shaping economic policy.