Which condition is required for f(x)=x2−kx+4x−2f(x) = \frac{x^2 - kx + 4}{x-2}f(x)=x−2x2−kx+4 to have a removable discontinuity at x=2x=2x=2?
k=4k = 4k=4
k=2k = 2k=2
k=6k = 6k=6
k=−4k = -4k=−4