Explanation:

Fiscal policy is a key macroeconomic tool used by governments to influence economic conditions, primarily through the manipulation of public finance. * **Correct Option (D) Government's Revenue and Expenditure:** Fiscal policy fundamentally refers to the government's decisions regarding its revenue (mainly through taxation) and expenditure (on public goods, services, and transfers). It is used to achieve objectives such as economic growth, price stability, and full employment. For example, during a recession, the government might increase spending or cut taxes to stimulate demand, while during inflation, it might do the opposite. * **Incorrect Option (A) Money supply in the economy:** Money supply is primarily managed by the central bank (e.g., Reserve Bank of India) through monetary policy. Tools like interest rates, reserve requirements, and open market operations are used to control the availability and cost of money in the economy, which is distinct from fiscal policy. * **Incorrect Option (B) Regulation of the banking system:** The regulation of the banking system is also a function of the central bank and other financial regulatory bodies. It falls under monetary policy and financial supervision, ensuring the stability and integrity of the financial sector, not fiscal policy. * **Incorrect Option (C) Planning for economic development:** While fiscal policy is an important instrument for achieving economic development goals, 'planning for economic development' is a much broader concept that encompasses various strategies, policies, and institutional frameworks across different sectors. Fiscal policy is a *component* or *tool* within the larger framework of economic development planning, but not synonymous with it.