Q. Which of the following countries have an Unwritten Constitution?

Explanation by: Mr. Dubey

An uncodified or unwritten constitution is a type of constitution where the fundamental rules of government take the form of customs, usage, precedent and a variety of statutes and legal instruments. Current example of such a constitution is United Kingdom of Great Britain and Northern Ireland where there is no defining document that can be termed "the constitution". Because the political system evolved over time, rather than being changed suddenly in an event such as a revolution, it is continuously being defined by acts of Parliament and decisions of the Law Courts