Direction of the electric field

[soopo]

Homework Statement

The problem is as an attachment.

The Attempt at a Solution

The right answer is (a).
However, I do not understand why.

I draw two circles around the A and B. I let A's electric field go to anticlockwise direction, while that of B to clockwise direction.

I got the result that electric field points from D to C.
However, my answer is wrong.

 

[dx]

What do you mean anticlockwise and clockwise? The electrostatic field of a point charge points radially. If the charge is positive, it points outward radially. If the charge is negative, it points inward radially. The magnitude is proportional to q/r².

 

[soopo]

What do you mean anticlockwise and clockwise? The electrostatic field of a point charge points radially. If the charge is positive, it points outward radially. If the charge is negative, it points inward radially. The magnitude is proportional to q/r².

Thank you for your answer!

I got finally that the electric field is from A to B.
I had confused electric field apparently with Magnetic field.

The key in allowing me to understand the problem was to set a positive test mass between two charges.