7. The logistic equation on the right is used to describe the rate of change of a population, N, with time, t, where r is the intrinsic rate of increase and K is the carrying capacity. Which of the following statements is true for this equation?

(A) For a given population, r is variable. 
(B) For a given environment, K is variable.
(C) As Napproaches K, dN/dt approaches 0.
(D) As N approaches K, dN/dt approaches K.
(E) As N approaches K, dN/at approaches r.