Java / Trees: Which node in a tree does not have a parent? Multiple chocie. center null root leaf

What kind of tree do you get back when you use a tree from the Java Standard Library to store data in an order?

In Java for the RedBlackTree how would you make the InsertFixup and RemoveFixup with the following RedBlackTree and BInNode class...   public class BinNode{private String data;private BinNode left;private BinNode right;private int height; //height field as with AVL tree or Red Black Treeprivate boolean color; //Needed for Red Black Treepublic BinNode(){data = "";left = null;right = null;}public int getHeight() {return height;}public void setHeight(int height) {this.height = height;}public BinNode(String d){data = d;left = null;right = null;}public void setData(String d){this.data = d;}public String getData(){return this.data;}public void setLeft(BinNode l){this.left = l;}public BinNode getLeft(){return this.left;}public void setRight(BinNode r){this.right = r;}public BinNode getRight(){return this.right;}}   public class RedBlackTree {private BinNode root;private BinNode nil;public RedBlackTree() {nil = new BinNode();nil.setColor(false); // Black color for NIL nodesroot = nil;}public…

Java / Trees: *Please refer to attached image* What is depth of Node W in this tree? Multiple chocie. 0 1 2 3 4 10