An article in the Wall Street Journal states that in Europe, “the continued decline in business sentiment contrasts with a slight revival in optimism among consumers.” What components of aggregate expenditure would a decline in “business sentiment” and an increase in consumer “optimism” affect? Holding constant other factors affecting the European economy, can we tell whether the two changes mentioned in the article will cause real GDP to increase or to decrease? Illustrate your answer with a 45°-line diagram.