3. Given the quadratic function $y=x^{2}+b x-3(-2 \leqslant b$ $\leqslant 2$ ), as $b$ changes from -2 to 2, the corresponding parabola also moves. Among the following descriptions about the direction of the parabola's movement, the correct one is ( ).
(A) First moves to the upper left, then to the lower left
(B) First moves to the lower left, then to the upper left
(C) First moves to the upper right, then to the lower right
(D) First moves to the lower right, then to the upper right
3. A.

The movement of the parabola's position is consistent with the movement of the vertex $\left(-\frac{b}{2},-\frac{b^{2}+12}{4}\right)$. As $b$ changes from -2 to 2, $-\frac{b}{2}$ continuously decreases, so it always moves to the left; while $-\frac{b^{2}+12}{4}$ first increases and then decreases, so it first moves upwards and then downwards.