The graph represents the motion of an object moving in one dimension. What is the object's average acceleration between t $=2$ and t $=12$ s$?$

graph.gif

Group of answer choices

$1\mathrm{.}5$ m$/$s$2$

$0\mathrm{.}2$ m$/$s$2$

$0\mathrm{.}83$ m$/$s$2$

$0\mathrm{.}67$ m$/$s$2$

$0\mathrm{.}5$ m$/$s$2$