By which Amendment were ‘Fundamental Duties’ added to the Constitution?

By which Amendment were ‘Fundamental Duties’ added to the Constitution? [SSC CGL Exam 27/08/2016, Shift II], [SSC Combined Graduate Level Exam 27/07/2008, Shift II]

          a) 40^th Amendment

          b) 42^nd Amendment

          c) 44^th Amendment

          d) 45^th Amendment