The correct answer is option 3: 42nd Amendment. The Fundamental Duties were added to the Constitution of India through the 42nd Amendment Act, which was passed in 1976.

Option 1, the 24th Amendment, is incorrect. The 24th Amendment Act, passed in 1971, dealt with the issue of election disputes.

Option 2, the 39th Amendment, is also incorrect. The 39th Amendment Act, passed in 1975, was aimed at reversing the judgment of the Supreme Court in the Kesavananda Bharati case and expanding the power of the government.

Option 4, the 44th Amendment, is incorrect as well. The 44th Amendment Act, passed in 1978, brought about several changes to the Constitution, including the restoration of certain fundamental rights.

Therefore, the correct answer is option 3, the 42nd Amendment, which introduced the Fundamental Duties into the Constitution of India.