  0.  $P(z_0)\neq\emptyset$ and $\bigoplus\limits_{\mu\in P(z_0)}{\mathbb{V}}_{-\Delta}(\mu)$ is a nontrivial $N(K)$-representation or $P(z_0)\neq\emptyset$ and $\bigoplus\limits_{\mu\in P(z_0)}{\mathbb{V}}_{-\Delta}(\mu)$ is a nontrivial $N(K)$-representation,  0.  $a(z_0)+c(z_0)<0<a(z_0)+c(z_0)$