Four Tiny Charged Particles (Two Having a Charge +Q and Two

Multiple Choice

Four tiny charged particles (two having a charge +Q and two having a charge -Q) are distributed on the x- and y-axes as shown in the figure. Each charge is equidistant from the origin. In which direction is the net electric field at the point P on the y-axis?

A) directly up (in the +y direction)
B) directly left (-x direction)
C) upwards and towards the left
D) upwards and towards the right
E) The net field is zero, so there is no direction.