The necessary and sufficient condition on the impulse response for stability is:
1
\(\mathop \sum \limits_{k = 0}^1 \left| {h\left( k \right)} \right| = \infty \)
2
\(\mathop \sum \limits_{k = - \infty }^0 \left| {h\left( k \right)} \right| > \infty \)
3
\(\mathop \sum \limits_{k = - \infty }^\infty \left| {h\left( k \right)} \right| < \infty \)
4
\(\mathop \sum \limits_{k = 0}^\infty \left| {h\left( k \right)} \right| > \infty \)