The system function of an LTI system is given by
$$H(Z)=\frac{1-\frac{1}{3}Z^{-1}}{1-\frac{1}{4}Z^{-1}}$$
The above system can have stable inverse if the region of convergence of $H(Z)$ is defined as
- $|Z|<\frac{1}{4}$
- $|Z|<\frac{1}{12}$
- $|Z|>\frac{1}{4}$
- $|Z|<\frac{1}{3}$