A plant has an open-loop transfer function,
$$G_p(s)=\frac{20}{(s+0.1)(s+2)(s+100)}$$
The approximate model obtained by retaining only one of the above poles, which is closet to the frequency response of the original transfer function at low frequency is
- $\frac{0.1}{s+0.1}$
- $\frac{2}{s+2}$
- $\frac{100}{s+100}$
- $\frac{20}{s+0.1}$