Two particles are separated by a distance d$.$Particle A has a charge $+$Q and particle B has a charge $+4$Q$.$At what distance from particle A along the line connecting particles A and B would you place a third charged particle such that no net electrostatic force acts on it$?$ Draw it$.$

a$)$d$/2$

b$)$d$/3$

c$)$d$/4$

d$)$d$/6$

e$)$d$/9$