SAT Question 9f2ecade: Nonlinear Functions answer and explanation with Desmos solution

Since $-5$, $6$, and $7$ are zeros of the function, the function can be rewritten as $h(x)=(x+5)(x-6)(x-7)$. Expanding the function yields $h(x)=x^3-8x^2-23x+210$. Thus, $a=-8$, $b=-23$, and $c=210$. Therefore, the value of $c$ is $210$.