Option 1 -> Autonomous consumption is the minimum consumption that occurs regardless of income level, not related to demand-supply equilibrium.
Option 2 -> Effective demand is the point where aggregate demand equals aggregate supply in an economy.
Option 3 -> Excess demand occurs when aggregate demand exceeds aggregate supply, creating inflationary pressure.
Option 4 -> Deficient demand occurs when aggregate demand falls short of aggregate supply, leading to unemployment.
Hence, Effective demand -> Effective demand represents the equilibrium point in an economy where the level of aggregate demand is exactly matched by aggregate supply. This concept was popularized by John Maynard Keynes, who argued that the economy reaches equilibrium at the point of effective demand, which may not necessarily be at full employment. At this point, producers are willing to supply exactly what consumers and other economic agents are willing to demand, creating a balance in the economy. -> correct