2. In the Cartesian coordinate system $x O y$, the line $y=a x+24$ forms a triangle with the positive axes of the two coordinates, and the area of this triangle is 72. Then the coordinates of the point not on the line are ( ).
(A) $(3,12)$
(B) $(1,20)$
(C) $(-0.5,26)$
(D) $(-2.5,32)$
2. D.

The line $y=a x+24$ intersects the positive x-axis at the point $\left(-\frac{24}{a}, 0\right)$, and the positive y-axis at the point $(0,24)$. This gives the lengths of the two legs of the right triangle as 24 and $-\frac{24}{a}$, and the area is
$$
\frac{1}{2} \times 24 \times\left(-\frac{24}{a}\right)=-\frac{288}{a} .
$$

According to the problem, $-\frac{288}{a}=72 \Rightarrow a=-4$.
Thus, the given line is $y=-4 x+24$.
Upon verification, $(-2.5,32)$ does not satisfy the line equation $y=-4 x+24$.