Let $A = \begin{pmatrix} 1 & 0 \\ 1 & 1 \end{pmatrix}$ and $B = \begin{pmatrix} 0 & 1 \\ 0 & 0 \end{pmatrix}$. If $M = \sum_{k=1}^{20} (A^k + B^k)$, then $\det(M)$ is equal to\\ (1) 100\\ (2) 200\\ (3) 0\\ (4) 400