Why Is 1648,marked by the Creation of the Treaties of Westphalia,a

Why is 1648,marked by the creation of the Treaties of Westphalia,a seminal year for scholars of international relations?

A) It marked a decrease of religious authority in Europe and the rise of secular authority in the form of sovereign states.
B) The Treaty of Westphalia failed and the Thirty Years' War began,ushering in the era of modern warfare.
C) It marked the rise of religious authority in the form of the Pope and the Catholic Church.
D) The Roman Empire fell that year,and Charlemagne rose to power.