As It Relates to Economic Growth, the Term Long-Run Trend

As it relates to economic growth, the term long-run trend refers to

A) the long-run increase in the relative importance of durable goods in the U.S.economy.
B) the long-term expansion or contraction of business activity that occurs over 50 or 100 years.
C) fluctuations in business activity that average 40 months in duration.
D) fluctuations in business activity that occur around Christmas, Easter, and other major holidays.