Which relations are functions? choose all answers that are correct. a. x –1 1 3 3 y 2 3 4 5 b. a parabola, opening down, is graphed on a coordinate grid. the parabola goes through point 0, 5, point 2, 1, and point negative 2, 1. c. {(−2, 4), (−1, 2), (1, 2), (3, 5)} d. a set of points are plotted on a coordinate grid. the points include point negative 3,3, point negative 1, 1, point negative 1, 6, point 1, 4, point 2, 1, and point 3, 2.