Ans: B.Australian Constitution. 

Exp:

Australian Constitution: Principle of co-operative federalism, Freedom of inter-state trade, commerce and intercourse, Idea of concurrent list.

UK Constitution: Law making procedures, Parliamentary Government, Rule of Law, Single citizenship, Cabinet system.

US Constitution: Fundamental Rights, Independent judiciary, Judicial review, Procedure for the removal of the judges of the Supreme court and High courts, Role of Vice President

Irish Constitution: Directive Principles of State Policy, The method of the presidential election, Nominating members of Rajya Sabha.