If $A=\begin{bmatrix} i & -i \\ -i & i \end{bmatrix}$ and $B=\begin{bmatrix} 1 & -1 \\ -1 & 1 \end{bmatrix}$ then $A^8$ equals

Question

$\begin{array}{1 1} 4B \\ 128B \\ -128B \\-64B \end{array} $