The correct answer is C. The Huns devastated large parts of the Roman Empire.
Although they did not conquer the territory of the empire, the devastation that they caused made other Germanic peoples could enter without major efforts, which in the end was the cause of the fall of the Western Roman Empire.
The words that comes in the blank space is "chief of staff".
The absolute most imperative piece of an effective group is a chief of staff sufficiently solid to be a fair representative. Weak head of staff are the most compelling motivation battles fumble. The chief of staff, when given legitimate expert, acts at the guardian to the competitor, guaranteeing that those requesting his consideration are acting strongly with whatever remains of the group and not offering independent guidance.
There is a multitude of ways in which our leaders reach us personally.
For example,
Teachers are leaders that are more specialized in helping students, and there are some, such as counselors that are even more personally.
A more general way that we are reached is through laws. We choose our laws, and they in return enforce it. Such as building roads, or helping develop towns.
Well, personally I think that it is flawed: it limits the inflow of new ideas into politics.
I think that one way to address it is to abolish the electoral college and introduce country-wide representative elections and not a "winner takes it all" system.