The vertices of triangle ABC are A (1,5), B (3,9), and C (5,3). The vertices of triangle DEF are D (-3,3), E (-2,5), and F (-1,2). Which conclusion is true about the triangles? A. The ratio of their corresponding sides is 1:3.

B. They are congruent by definition of congruence in terms of rigid motions.

C. The ratio of their corresponding angles is 1:3.

D. They are similar by definition of similarity in terms of a dilation.