Why are corresponding exterior angles of similar triangles congruent? because the sum of the measures of the interior angles of a triangle always equal 90°, so the sum of the measures of the exterior angles must always be the same

B
because the sum of the measures of the interior angles of a triangle always equal 180°, so the sum of the measures of the exterior angles must always be the same

C
because corresponding interior angles are congruent, and the sum of the measures of an interior angle and an adjacent exterior angle always equals 90°

D
because corresponding interior angles are congruent, and the sum of the measures of an interior angle and an adjacent exterior angle always equals 180°