Determine the intervals of concavity for the graph of the function $g(x)=x{e}^{-x}.$

Note: This question closely resembles one of the supplemental examples in the video linked below.

$g(x)$ concave up on $(2,)$

$g(x)$ concave down on $(-,2)$

$g(x)$ concave down on $(-2,)$

$g(x)$ concave up on $(-,-2)$

$g(x)$ concave up on $(-2,)$

$g(x)$ concave down on $(-,-2)$

$g(x)$ concave down on $(2,)$

$g(x)$ concave up on $(-,2)$