Business cycles are: A. Predictable economic expansions above the long-termtrend. B. Irregular fluctuations in the level of economic activity,which rarely occur anymore. C. Periodic fluctuations in aggregate demand that depend on thetime of the year. D. Short-term patterns of increases and decreases in economicactivity around a general trend. E. Abrupt and unexpected departures from the current economictrend. . . .