8. Four lightweight balls A, B, C and D are suspended by threads. Ball A is attracted to a negatively charged pen. Below
are the interactions of the four balls when brought near each other in turn, and not allowed to touch. Based on this data,
what are the signs of each ball, +, -, or (N)eutral, listed in order of A, B, C, D?
I. A is attracted to B, C, and D
II. B and D have no effect on each other.
III. B is attracted to C.
(1) +, N, -, N
(2) -,+, N, N
(3) +, -, N, N
(4) -, N, +, N
(5)+,-,-,-