(d)
Since, $f(x)$ is continuous at $x = 0$
$\therefore\ \ \ \ \lim_{x \rightarrow 0}{f(x)} = f(0)$
$\Rightarrow \ \lim_{x \rightarrow 0}\frac{- e^{x} + 2^{x}}{x} = f(0)$
$\Rightarrow \ \ \lim_{x \rightarrow 0}\frac{- e^{x} + 2^{x}\log 2}{1} = f(0)$ [by L ‘Hospital’s rule]
$\Rightarrow f(0) = - 1 + \log 2$