Which of these factors contributed only to the fall of the han dynasty and not to the fall of the roman or gupta empires? (a) the empire broke into three kingdoms ruled by powerful lords. (b) external and internal forces weakened the empire. (c) leaders used tax money for their personal gain. (d)the empire was in a constant state of war. (e)public projects and trade declined. (f)famine swept through the region. ( pick more than one )