Which table represents a quadratic relationship?
a.
x -7 -6 -5 -4 -3 -2
f(x) 135 128 105 72 35 0
b.
x -2 -1 0 1 2 3
f(x) 4 2 1 0.5 0.25 0.125
c.
x -1 0 1 2 3 4
f(x) 90 56 26 0 -22 -40
d.
x -2 -1 0 1 2 3
f(x) -23.4 -23.2 -23 -22.8 -22.6 -22.4