Nathaniel writes the general form of the equation gm = cm + rg for when the equation is solved for m. He uses the general form to solve the equation –3m = 4m – 15 for m. Which expression shows what Nathaniel will actually evaluate? A. 4 + 15 – 3 B.4 – 15 + 3 C.-15/-3-4 D.–15 – -3/4