Final answer:
King William converted England into a feudal kingdom, which over time evolved into a constitutional monarchy after the Glorious Revolution when William and Mary accepted the English Bill of Rights. The correct option is A.
Step-by-step explanation:
King William converted England into a feudal kingdom after the conquest of England in 1066. However, the history of British monarchy evolved significantly over the centuries.
Following the English Civil War, the constitutional monarchy was established when William and Mary ascended to the throne as a result of the Glorious Revolution and accepted the English Bill of Rights, which limited their powers and recognized Parliament's authority.
This change was reflected when many starting as absolute monarchies transitioned to constitutional monarchies, where the monarch acts within the constraints of a constitution and usually with a ceremonial role. The correct option is A.