$6.$ Three equal charges are located in the x$-$y plane with coordinates $(0,3$m$),(4$m$,3$m$),$ and $(4$m$,$

$0).$ The direction of the force on the charge located at $(4$m$,3$m$)$ is the same as the direction of

a$.3$i $+4$j

b$.4$i $+3$j

c$.9$i $+16$j

d$.16$i $+9$j

e$.7$i $+7$j