$$
\begin{array}{l}
M=\left\{x \left\lvert\, x=\sin \frac{(2 m-3) \pi}{6}\right., m \in \mathbf{Z}\right\}, \\
N=\left\{y \left\lvert\, y=\cos \frac{n \pi}{3}\right., n \in \mathbf{Z}\right\} .
\end{array}
$$

Then the relationship between $M$ and $N$ is ( ).
(A) $M \subsetneq N$
(B) $N \varsubsetneqq M$
(C) $M=N$
(D) $M \cap N=\varnothing$
一, 1. B.
By periodicity, $M=N=\left\{ \pm 1, \pm \frac{1}{2}\right\}$.