Imagine a Single Charge Q Placed on One Corner of a Square

Multiple Choice

Imagine a single charge q placed on one corner of a square, and that the electric field at the center of the square is F/q. If additional equal charges are placed on the other three corners, the electric field at the center of the square due to these four equal charges is

A) F/q.
B) 4F/q.
C) F/(2q) .
D) F/(4q) .
E) none of the above