Final answer:
Recessions typically include at least two consecutive quarters of declining real GDP, which stems from the definition of a recession within the framework of the business cycle.
Step-by-step explanation:
Recessions are defined by a significant decline in real GDP. According to economic guidelines and historical patterns shown in, for instance, figure 6.10 which shows U.S. real GDP since 1900, a recession typically includes at least two consecutive quarters of declining real GDP. The 2008-2009 Great Recession is a recent example of this pattern.
The business cycle is a useful concept to understand these economic fluctuations, where the period of decline from the peak to the trough is recognized as a recession. An even more severe and prolonged economic downturn is known as a depression. Over a long period, real GDP has increased significantly but has experienced variations on a year-to-year basis, reflecting the inherent ups and downs of the economy.
Considering the provided information and the average duration of recessions post-WWII being 11 months, the correct answer to the question is: Recessions typically, but not always, include at least two consecutive quarters of declining real GDP. The answer is therefore B. Two.