A particular force acting on object has equation $F=-cx^3$ where x is displacement of object from some orgin and $c=1N/m^3$ What is magnitude of the work done by this force, as the object moves from $x=-2m,\; to\;x=+2m$

Question

$$(a)\;16\;J \quad (b)\;8\;J \quad (c)\; 4\;J \quad (d)\;0\;J$$