three objects are brought close to one another, two at a time. when objects a and b are brought together, they attract. when objects b and c are brought together, they repel. which of the following are necessarily true? (select all that apply.) one object is neutral. objects a and c possess charges of the same sign. all three objects possess charges of the same sign. objects a and c possess charges of opposite sign. additional experiments must be performed to determine information about the charges on the objects.