What is the sequence of elements visited in the postorder traversal algorithm on the following Tree: 10 a. 3,5,4, 2, 7, 10, 9, 11, 8, 6,1 b.5.1,4,3,6, 2, 8, 7, 10, 9, 11 12,3,4,5,6, 7, 8, 9, 10, 11 d. 3, 2,5, 4, 2, 6, 9, 10, 8,11