Which of the following statements about exponential growth curves is true?
a.

exponential growth curves are common for r-selected species.
b.

exponential growth curves show fast growth rates followed by slow growth rates.
c.

no organisms in nature experience exponential growth rates.
d.

exponential growth curves are s-shaped.

The only statement that is true about exponential growth is :
a) Exponential growth curves are common for R-selected species.

Population growth in r-selected species grow/decay according to the exponential growth equation:
Delta N / Delta t = rN 

We know that in reality, it is not possible for population growth to continue indefinitely.