$n$阶行列式
$$
\left|\begin{array}{cccccc}
a & b & 0 & \cdots & 0 & 0 \\
0 & a & b & \cdots & 0 & 0 \\
0 & 0 & a & \cdots & 0 & 0 \\
\vdots & \vdots & \vdots & & \vdots & \vdots \\
0 & 0 & 0 & \cdots & a & b \\
b & 0 & 0 & \cdots & 0 & a
\end{array}\right|_{n \times n}
$$
得值为
$\text{A.}$ $a^n+(-1)^{n+1} b^n$
$\text{B.}$ 0
$\text{C.}$ $a^n-b^n$
$\text{D.}$ $a^n+b^n$