Two Ions Are Placed on the X-Axis

Multiple Choice

Two ions are placed on the x-axis.One has a charge of + e and is located at the origin.The other has a charge of -4e and is located at x = + d,where d > 0.Where on the x-axis is the net electric field equal to zero?

A) x = -2d
B) x = -d
C) x = + d
D) x = + 2d