Explanation

(d)
$\frac{1}{(x - 1)^{2}(x - 2)} = \frac{1}{- 2(1 - x)^{2}\left( 1 - \frac{x}{2} \right)}$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ = - \frac{1}{2}\left\lbrack (1 - x)^{- 2}\left( 1 - \frac{x}{2} \right)^{- 1} \right\rbrack$
$\ \ \ \ \ \ \ \ \ \ \ = - \frac{1}{2}\left\lbrack (1 + 2x + \ldots)\left( 1 + \frac{x}{2} + \ldots \right) \right\rbrack$
$\therefore Coefficient\ of\ constant\ term\ is - \frac{1}{2}$.