When a Single Charge Q Is Placed on One Corner

Multiple Choice

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

A) F/q.
B) F/(2q) .
C) F/(4q) .
D) 4F/q.
E) None of the above choices are correct.