If U = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12} and A = {1, 4, 6, 8, 9}, what is A′?

  • {2, 3, 5, 7, 10, 11, 12}
  • {1, 4, 6, 8, 9}
  • {}
  • {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}