Choices A, C, and D are theorems that prove congruence,
not similarity.
Choice B proves similarity. Since the sum of the angles in every
triangle is the same number (180°), if two angles of one triangle
are equal to two angles of the other triangle, then the third angles
in each one must also be equal. AND if all the angles in one triangle
are equal to all the angles in the other one, then the triangles are similar.
