Which pair of values exhibits a proportional
relationship?
(2, 5), (4, 10), (6, 15), (8, 20)
(3, 7), (6, 9), (9, 12), (12, 15)
(1, 4), (2, 9), (3, 16), (4, 25)
(5, 3), (10, 5), (15, 9), (20, 11)