Laplace transform of a signal $x(t)$ is
\[
X(s)=\frac{1}{s^{2}+13 s+42}
\]
Let $u(t)$ be the unit step function. Choose the signal $x(t)$ from the following options if the region of convergence is $-7<\operatorname{Re}\{s\}<-6$.</p>
$-e^{-6 t} u(t)-e^{-7 t} u(-t)$
$-e^{-6 t} u(-t)-e^{-7 t} u(t)$
$e^{-6 t} u(t)-e^{-7 t} u(-t)$
$-e^{-6 t} u(-t)-e^{-7 t} u(-t)$