2. (20 marks) Binary tree traversals: Give the prefix, infix, and postfix expressions corresponding to the binary tree shown below. a. b. Write the preorder, inorder and postorder traversals of the binary tree shown below A binary tree has a preorder traversal of ECDFKJMOGHILNPQ and an inorder traversal of CKFDMJOEHGLPNQI. What is its postorder traversal of this binary tree? Given the following combinations, which one you can use to construct a unique binary tree? If a combination cannot be used to uniquely identify a binary tree, please give an example to show this. Combination 1: preorder traversal sequenceinorder traversal sequence; Combination 2: preorder traversal sequence+postorder traversal sequence; Combination 3: inorder traversal sequence +postorder traversal sequence c. d