17. Two conductive balls of the same size are put near each other, but not touching. One of the balls is charged with a total charge Q. The other ball has zero total charge. Which of the following is correct?
(A) The balls attract each other
(B) The balls repulse each other
(C) There is no force between them
(D) The balls attract each other at long distance, but repulse each other at short distance
(E) The balls attract each other if Q ＞ 0, but repulse each other otherwise.