To solve this problem, we need to determine when the growth rate of a population following the logistic model equals zero. The logistic model is given by:$\newline \frac{dN}{dt} = rN\left(1 - \frac{N}{K}\right)\newline$The growth rate is zero when $\frac{dN}{dt} = 0.\newline$Let's set the equation to zero and solve for $N:\newline rN\left(1 - \frac{N}{K}\right) = 0\newline$This equation is zero when either $rN = 0$ or $\left(1 - \frac{N}{K}\right) = 0.\newline \bullet$If $rN = 0,$ then $N = 0.$ This means the population size is zero, which is not a typical scenario for a stable population.$\newline \bullet$If $\left(1 - \frac{N}{K}\right) = 0,$ then $\frac{N}{K} = 1.\newline$This implies that $N = K,$ meaning the population size equals the carrying capacity.$\newline$Therefore, the growth rate of the population is zero when $N/K$ is exactly one.$\newline$This corresponds to Option 1.