(c)
$\lim_{x \rightarrow 0}\left\lbrack \frac{e^{\sin x} - e^{x}}{\sin x - x} \right\rbrack = \lim_{x \rightarrow 0}\left\lbrack \frac{e^{x}(e^{\sin{x - x}} - 1)}{\sin x - x} \right\rbrack$
$= \lim_{x \rightarrow 0}\ e^{x}\ \lim_{x \rightarrow 0}\left\lbrack \frac{e^{\sin{x - x}} - 1}{\sin{x - x}} \right\rbrack$
$= e^{0} \times 1 = 1$