Which of these sets of ordered pairs satisfies an exponential equation? (1) {(1, -1), (2, -8), (3, -27), (4, -64)} (2) {(1, -1), (2, -4), (3, -9), (4, -16)} (3) {(1, -2), (3, -8), (5, -32), (7, -128)} (4) {(1, -2), (3, 2), (5, 6), (7, 10)}