Explanation

(d)
Given equation of line is
${kx}^{2} - 2xy - y^{2} - 2x + 2y = 0$
On comparing with standard equation, we get
$a = k\ ,\ b = - 1,\ h = - 1,\ g = - 1,\ f = 1,\ c = 0$
It represent a pair of lines, if
$k( - 1)(0) + 2(1)( - 1)( - 1) - k{(1)}^{2} - ( - 1){( - 1)}^{2} - 0{( - 1)}^{2} = 0$
$\Rightarrow \ 0 + 2 - k + 1 = 0\ \Rightarrow \ k = 3$