Which of the Following Statements Is FALSE

Which of the following statements is FALSE?

A) Changes in real GDP can cause changes in an economy's level of employment.
B) The U.S. economy tends to operate at a particular level of output for a long period of time.
C) The general level of prices in an economy can be affected as output expands toward full employment.
D) The level of activity in a market economy is always going through periods of expansion and contraction.