Two cables are securing a kayak to a roof rack. The forces are represented by vectors vec$(u)=($:$-5,6,3$:$)$ and vec$(t)=($:$-8,-2,1$:$).$ If both cables are replaced by a single cable, what vector would represent the cable? $($:$3,8,2$:$)($:$-13,4,4$:$)($:$-3,-8,-2$:$)($:$13,-4,-4$:$)$