Answer
choice $(B)$
Work Step by Step
Equation form:
$\displaystyle \quad f(x)=\frac{N}{1+Ab^{-x}}$,
where $N$ = limiting value,
Reading the graph, we have:
$N=8,$ no choice is eliminated.
It is a decreasing graph, $b\lt 1$, which eliminates (C)
$f(0)=2\Rightarrow\left\{\begin{array}{ll}
2 & =\dfrac{8}{1+Ab^{0}}\\
1+A & =8/2\\
A & =4-1=3
\end{array}\right.\qquad\Rightarrow\qquad $choice $(B)$
