Examine the diagram.

Lines b and a intersect lines c and d to form 16 angles. At the intersection of lines b and c, clockwise from top left, the angles are 1, 2, 4, 3. At a and c, clockwise from top left, the angles are 5, 6, 8, 7. At b and d, clockwise from top left, the angles are 13, 14, 16, 15. At a and d, clockwise from top left, the angles are 9, 10, 12, 11.

Name two corresponding angles to ∠1.
∠6 and ∠15
∠5 and ∠6
∠13 and ∠15
∠5 and ∠13
100 points :)