111.A positive point charge exerts a force of magnitude F on a negative point charge placed a distance x away. The negative point charge is replaced with a positive point charge and the distance between the two point charges is halved. What is the magnitude of the new force that the positive point charge exerts on the negative point charge?
(A) 4F
(B) 2F
(C) F
(D) F/2
(A) 4F
(B) 2F
(C) F
(D) F/2