Given f, of, x, equals, 2, x, cubed, minus, 6, x, plus, kf(x)=2x³ ?6x k, and the remainder when f, of, xf(x) is divided by x, minus, 2x?2 is 2121, then what is the value of kk?
a) 2
b) 3
c) 4
d) 5