The statement that best describes the development of England as a nation-state is:
B. As the need for protection gradually decreased, feudalism was replaced by monarchs who ruled by laws and legal precedent. Eventually, Parliament became more powerful than the monarch.
This statement captures the transition from a feudal system to a more centralized monarchy, and it correctly indicates the eventual rise of Parliament as a significant power in England, which began to challenge and limit the authority of the monarchy, especially after events like the signing of the Magna Carta in 1215.