Which of the following statement is correct?

It has been clarified by the Supreme Court of India that, Preamble is a part of the Constitution and can be subjected to Constitutional Amendments exercised under article 368, however, the basic structure cannot be altered. Therefore, it is considered as the heart and soul of the Constitution. The ‘Preamble’ of the Constitution of India is a brief introductory statement that sets out the guiding purpose and principles of the document, and it indicates the source from which the document which derives its authority, meaning, the people. It was adopted on 26 November 1949 by the Constituent Assembly of India and came into effect on 26th January 1950. As of now, the preamble is only amended once through the 42nd Amendment Act, 1976.