Study the following diagram of the labour market. Which one of the following statements is correct? The diagram illustrates ___ Select one: A. a higher mark-up accompanied by an increase in the natural rate of unemployment. B. an increase in the actual price level accompanied by a decrease in the natural rate of unemployment. C. a lower mark-up accompanied by an increase in the natural rate of unemployment. D. a decrease in the price determined real wage accompanied by a decrease in the natural rate of unemployment.