Is the discrete time LTI system with impulse response h=an (|a| < 1) BIBO stable?

• A two-sided sequence (neither left nor right-sided) has a ROC consisting of a ring in the z-plane, bounded on the interior and exterior by a pole
• The ROC cannot contain any poles
• ROC is a disconnection region Correct
• The Fourier transform of x[n] converges absolutely if and only if the ROCof the z-transform includes the unit circle