Answer: I disagree with the person that answers before. The answer is D, parliamentary democracy.
Here's why: The definition of parliamentary democracy is a democratic form of government in which the party with the greatest representation in the parliament (legislature) forms the government, its leader becoming prime minister. The United Kingdom is a unitary state with devolution that is governed within the framework of a parliamentary democracy under a constitutional monarchy in which the monarch, currently Queen Elizabeth II, is the head of state while the Prime Minister of the United Kingdom, is currently Boris Johnson
