The correct answer is Prof. Walker Explanation & Key Takeaways: • Prof. Walker is credited with the statement "Money is what money does." • The statement emphasizes the functional definition of money, focusing on its role and activities in the economy rather than its intrinsic properties. • Money serves several key functions: a medium of exchange, a unit of account, a store of value, and sometimes, a standard of deferred payment. • This perspective aligns with the pragmatic approach in economics, where the utility and effectiveness of money are determined by its practical applications. Related Concepts: • Prof. Walker was an influential economist whose work significantly impacted monetary theory. • The pragmatic view of money has been pivotal in understanding its evolving forms, from physical currency to digital money. • This definition underscores the adaptability of money to different economic contexts and technological advancements. • Understanding the functions of money helps in grasping the broader economic principles and the impact of monetary policy.