Select the correct answer from the drop-down menu. A transversal t intersects two parallel lines a and b, and forms two groups of angles. On top line a, starting from the top left, clockwise, angles are 1, 2, 3, and 4. On below line b, starting from the top left, clockwise, angles are 5, 6, 7, and 8. In the figure, transversal t intersects the parallel lines a and b. ∠2 ≅ ∠7 The theorem by which they are congruent is the .