(a) How many internal nodes are there in T? 6 (b) Give the preorder and postorder traversals of the T. preorder: a, b, d, e, g, c, f, h, i postorder: d, g, e, b, i, h, f, c, a (c) At least how many nodes do you have to add to T to make it a full binary tree? 4 (d) At least how many nodes do you have to add to T to make it a complete binary tree? 17 a T: d b e g f i C h