2. Given the set of points on the plane
$$
\begin{array}{l}
M=\left\{(x, y) \mid y=\sqrt{2 x-x^{2}}\right\}, \\
N=\{(x, y) \mid y=k(x+1)\} .
\end{array}
$$

When $M \cap N \neq \varnothing$, the range of values for $k$ is ( ).
(A) $\left[-\frac{\sqrt{3}}{3}, \frac{\sqrt{3}}{3}\right]$
(B) $\left[0, \frac{\sqrt{3}}{3}\right]$
(C) $\left[-\frac{\sqrt{3}}{3}, 0\right]$
(D) $\left[\frac{\sqrt{3}}{3},+\infty\right)$
2. B.

From the geometric meaning of point sets $M$ and $N$, we can easily know.