केन्स यांचा उत्पन्न व रोजगार सिद्धांत असे गृहीत धरतो की

The correct answer is Option A (Wages and prices remain constant).

Key Points:
• Keynesian Macroeconomics: In his 1936 masterpiece, *"The General Theory of Employment, Interest and Money"*, John Maynard Keynes revolutionized economic thought, primarily focusing on the short-run.
• Sticky Wages and Prices: A fundamental assumption of the basic Keynesian model is that in the short run, wages and prices are "sticky" (rigid or constant) downward. Unlike Classical economists who believed wages and prices flexibly adjust instantly to clear markets (ensuring full employment), Keynes argued that institutional factors (like labor unions and contracts) prevent wages from falling during a recession.
• Implication: Because prices and wages are assumed constant in the short run, the Aggregate Supply curve is horizontal. Therefore, any change in output and employment is entirely determined by changes in Aggregate Demand.
• Rejection of Options: Keynes never assumed income and consumption remain constant; rather, consumption is a function of income (C = a + bY). Hence, option 1 is the only correct assumption framing his short-run framework.
• Key Takeaway: Keynesian short-run theory assumes 'sticky' or constant wages and prices, meaning employment is determined solely by Aggregate Demand.