Answer:
(D). An increase in employment, production, and income.
Step-by-step explanation:
According to Keynes, when wages and prices are sticky, they do not respond to changes (whether increases or decreases) in demand.
Therefore, when the aggregate demand curve shifts to the right, price level remains the same due to price stickiness, however, real Gross Domestic Product (GDP) increases and this causes an increase in employment, production and income.