Question $8(1$ point$)$

The function $f(x)=x^3+a{x}^2+b$ has a critical value $at(0,8),$

Find the constants a and $b.$

$a=-4$ and $b=8$

$a=4$ and $b=-8$

$a=-8$ and $b=3$

$a=0$ and $b=-8$