During Unit SE$,$ we learned that $+$ and $-$ charges are part of the model we used for explaining the interactions between electrically charged objects. For their initial models of magnetism, in Unit M$,$ some groups in class assumed the unrubbed nail contained separate north and south entities distributed randomly throughout the nail. Other groups assumed the unrubbed nail contained separate $+$ and $-$ entities distributed randomly throughout the nail. Although, at the time, these initial Models were developed. We did not have evidence to help us decide whether one set of entities, either North and South, or $+$ and $-,$ Was any better than the other set? We eventually came up with evidence that supported the idea that we should use different types of entities for models of magnetism and static electricity phenomena.of the following statements, which represents the best evidence to suggest it would actually not be appropriate to use the separate $+$ and $-$ entities to describe both magnetic and electrostatic phenomena.A$.$ Magnetic objects can both attract and repel each other, but electrically charged objects can only attract each other.B$.$ We observed that the two ends or sides of a magnetized object behaved differently when interacting with another magnetized object, but the two ends or sides of an electrically charged object behaved the same when interacting with another electrically charged object.C$.$ An electrically charged object can only attract an uncharged object when they are in contact, whereas a magnet can attract any ferromagnetic object at a distance.D$.$ Opposite type entities attract each other in magnetism, but opposite type entities repel each other in static electricity.