A plum is located at coordinates $(-1\mathrm{.}49m,0,3\mathrm{.}94m).$ In unit$-$vector notation, what is the torque about the origin on the plum if that torque is due to a force vec$(F)$ whose only component is $($a$)F_x=1\mathrm{.}25N,($b$)F_x=-1\mathrm{.}25N,($c$)F_z=1\mathrm{.}25N,$ and $($d$)F_z=-1\mathrm{.}25N?$