The correct answer is John Maynard Keynes.John Maynard KeynesHe organized the idea of deficit financing as compensatory spending meant to solve the problem of unemployment and depression. Hence, Option 3 is correct.Modern economists prescribe deficit financing for developmental purposes.Important PointsDeficit Financing It can be defined as the practice where the government spends more money than it receives as revenue, the difference being made up by borrowing or minting new funds.It can happen when the total income of the government (revenue account + capital account) falls below its total expenditure.The government resorts to withdrawing money from its cash deposited in the RBI or orders the RBI to print new currency notes or borrows money from the public in the form of bonds and other securities.The deficit is financed by borrowing loans from the central bank, commercial banks, and even state governments through Ad-hoc Treasury Bills.Additional InformationAdam Smith He was a Scottish economist and also known as the Father of economics or the Father of Capitalism.Adam Smith's work includes The Theory of Moral Sentiments(1759)An Inquiry into Nature and Causes of the Wealth of Nations. (1776)Economics is a social science concerned with the production, distribution, and consumption of goods and services. It studies how individuals, businesses, governments, and nations make choices about how to allocate resources. Alfred Marshall.The general principles of pricing were given by Alfred Marshall.Principles of Economics is an economics textbook by Alfred Marshall, first published in 1890. The Theory of Supply and Demand was given by Alfred Marshall in 1890.The Theory of Demand and Supply is a central concept in the understanding of the Economic system and its function.The quantity demanded of a good or service is the amount that consumers plan to buy during a particular time period, and at a particular price.Milton Friedman.?The 'natural rate of unemployment hypothesis' was advocated by Milton Friedman.According to this hypothesis, a minimum level of unemployment was important to prevent a continuous rise in inflation levels.This would ensure lesser demand in the market because of the decreasing purchasing power capacity of the potential workforce, which is still unemployed.