2. Let $a, b \in \mathbf{R}, a b \neq 0$, then the graph of the line $a x-y+b=0$ and the curve $b x^{2}+a y^{2}=a b$ is answer $(\quad)$
(B)
2.【Analysis and Solution】The given equations can be transformed into $y=a x+b$ and $\frac{x^{2}}{a}+\frac{y^{2}}{b}=1$, then it can be observed that the correct choice should be (B).