The Correct Answer is : 42nd Constitutional Amendment Act Explanation & Key Takeaways: • The 42nd Constitutional Amendment Act is popularly known as the 'Mini-Constitution' due to the extensive changes it brought to the Constitution of India. • Year of passing: The 42nd Amendment Act was passed in 1976 during the period of the Emergency in India (1975-1977) under the leadership of Prime Minister Indira Gandhi. • Changes to the Preamble: It made changes to the Preamble of the Indian Constitution, adding the terms 'Secular', 'Socialist', and 'Integrity'. • Centralized Authority: The amendment sought to reduce the powers of the Supreme Court and High Courts to pronounce upon the constitutional validity of laws. It also underlined the supremacy of the Parliament over the other two branches of the Government - the executive and the judiciary. • Fundamental Duties: It introduced a new section in the Constitution - Part IV A which deals with the Fundamental Duties of the Indian citizens. • Amendment of Directive Principles of State Policy: It added four directive principles to promote an international peaceful and harmonious order. • More Power to the Prime Minister: It brought changes in the operation of the Indian government by strengthening the Prime Minister's authority where the President can act only with the advice of the Prime Minister. • Increased term of Lok Sabha and State Assemblies: One of the most significant changes was increasing the term of Lok Sabha and Assembly from 5 Years to 6 Years, however, this was later reversed in the 44th Constitutional Amendment in 1978.