Knowledge is useless in the hands of those who don't know how to use it. Of course, if I knew how to manipulate people to such an extent as to garner their support, then knowledge is indeed power.
In todays society, money is all important, but as several of you have shown, money is only paper and has no intrinsic value. People are the most important factor without doubt. If 5 billion people supported me as a world leader, then I'm the world leader, simple as that. If this were to happen, I would control the money, the resources and everything else in this world. As such, I would have ultimate authority (rendering the third option obsolete).