Final answer:
Unemployment increases and GDP growth slows during the recessionary phase of the business cycle, which is a period marked by significant economic decline and typically begins at a peak and ends at a trough. The correct answer is option c.
Step-by-step explanation:
Unemployment rises and real Gross Domestic Product (GDP) growth slows during the c. Recessionary phase of the business cycle. This phase is marked by a significant decline in economic activity across the economy. When real GDP declines for an extended period, this signals a recession, which typically begins at the peak of the business cycle and ends at the trough. If the recession is especially lengthy and deep, it's termed a depression. Notable historical examples include the Great Depression of the 1930s and the Great Recession of 2008-2009.