The business cycle approach discussed in the reading enjoyed its boom years: in the 18th century. early in the 19th century. early in the 20th century. from 1950 until 1970. Choose the most correct answer by clicking a button, or by typing a letter from the keyboard and pressing the tab key. What is the difference between theories of business cycles and of business fluctuations? Cycles are periodic and fluctuations are irregular in occurrence. Fluctuations are periodic and cycles are irregular in occurrence. Cycles rely on feedback and fluctuations assume that there is no feedback. Fluctuations rely on feedback and cycles assume that there is no feedback. Choose the most correct answer by clicking a button, or by typing a letter from the keyboard and pressing the tab key.