The correct answer is D. He had few resources to fight off challengers.
Henry IV was the emperor of the Holy Roman Empire during the 11th century. This event happened during the investiture controversy, a political conflict between the emperor and the pope about the designation of bishops. In one of the episodes of this conflict, Henry IV was excommunicated by the pope and, in order to regain political resources in the Catholic Europe of that time, Henry IV went to Italy to seek for forgiveness and absolution of his excommunication. This trip is known as the humiliation of Canossa.