Instance Varables

Here is the start of the class Tree. Decide what the instance variables should be:

public class Tree
{
  // instance variables
  private double x, y, z;
  private 
  - pick one -
  double
  String
  Groot
  Cone
  Cylinder
   branches;
  private 
  - pick one -
  double
  String
  Treebeard
  Cone
  Cylinder
   trunk;
 
  ...
}