K Let D (16,19,21)}, E (16,18,19,20) and F (15,17,18,19,21) List the elements in the set (DUE) n F (DUE)= (Use a comma to separate answers as needed. List the elements in order with no duplicates.) (DUE)NF= (Use a comma to separate answers as needed List the elements in order with no duplicates.)