David drew a straight, non-vertical line. Then, he drew two right triangles, as shown in the figure, using a different segment of his line for the hypotenuse of each triangle. Which statement must be true?
The two triangles are similar, so the slopes of the hypotenuses of the two triangles must be the same.

The two triangles are similar, so the slopes of the hypotenuses of the two triangles must be different.

The two triangles are congruent, so the slopes of the hypotenuses of the two triangles must be the same.

The two triangles are congruent, so the slopes of the hypotenuses of the two triangles must be different.