Six Points and a Square

A small network takes a single number $x$ and computes

$u = w_1x + b_1, \qquad z = w_2\,f(u) + b_2, \qquad \text{with } f(u) = u^2$

That is two neurons with a non-linear function slipped in between them: $z = w_2 \cdot f(w_1x + b_1) + b_2$.

The network labels a point $+$ when $z > 0$ and $-$ when $z < 0$. You may set $w_1$, $b_1$, $w_2$ and $b_2$ to any real numbers, positive, negative or zero, as long as no point lands exactly on $z = 0$.

Six points sit at $x = 1, 2, 3, 4, 5, 6$. Each option lists their labels in that order, from $x = 1$ to $x = 6$.

Which labelling can no choice of the four parameters produce?