. The capitalist system of the United States is based on
O a. private property rights.
O b. the Bill of Rights.
O c. civil liberties.
O d. economic equality for all.

d. He defended papal authority against the rising power of laymen.

Explanation:

Marsilius of Padua (1280-1343) was a distinguished thinker and philosopher of the Middle Ages. He wrote the treatise Defensor Pacis, a major work of medieval political science. In Italy, he associated with the anti-papal Ghibellines. Among his arguments, the work holds that the unity of the state must be preserved by limiting the powers of the church hierachy. The source of all political power and the law is the people, who have the right to choose their ruler, he believed.