If a country is in a recessionary period, which of the following accurately describes the behavior of real GDP over time.

a. real GDP does not fluctuate, and follows a vertical sloping trend line
b.real GDP does not fluctuate and follows a horizontal trend line
c.real GDP fluctuates, but follows a downward sloping trend line
d.real GDP fluctuates, but follows a upward sloping trend line

c. real GDP fluctuates, but follows a downward sloping trend line