2.(i) (Grade 11) If the lengths of the three altitudes of a triangle are $12, 15, 20$, then the shape of the triangle is ( ).
(A) Acute triangle
(B) Right triangle
(C) Obtuse triangle
(D) Shape uncertain
(ii) (Grade 12) The vertex of the parabola is at the origin, the axis of symmetry is the $x$-axis, and the focus is on the line $3 x-4 y=12$. Then the equation of the parabola is $(\quad)$.
(A) $y^{2}=-12 x$
(B) $y^{2}=12 x$
(C) $y^{2}=-16 x$
(D) $y^{2}=16 x$
2. (i) B.

The ratio of the three sides of the triangle is $\frac{1}{12}: \frac{1}{15}: \frac{1}{20}=5: 4: 3$. Therefore, it is a right triangle.
(ii)D.
The focus of the parabola is the intersection point of the line $3 x-4 y=12$ with the $x$-axis, which is $(4,0)$. Suppose the equation of the parabola is $y^{2}=2 p x$. From $\frac{p}{2}=4$, we get $p=8$.