The correct Option is (d). In the United States for any amendment to take place the state legislature's 2∕3 rd majority, while in India the states have no power to initiate a constitutional amendment. It can only be initiated by Lok Sabha or Rajya Sabha. And only wherein the federal structure of the country is effected that requirement of half of state legislature's approval is required or in other words 50%. (e.g., In case of Goods and Services Tax). In Switzerland any amendment affecting the units require ratification by half of their existing number. In case of Australia the Federal government has no control over the Constitution of the units.