The values of $a$ and $b$ if $f(x)=x^4+x^3+8x^2+ax+b$ is divided by $x^2+1$ is _____

Question

$\begin{array}{1 1}(A) \;-1,7\\(B)\;1,-7\\(C)\;-1,-7\\(D)\;1,7\end{array}$