This question is just to narrow down some definitions:.
Consider a fully balanced binary search tree holding all the integers from 1 to 15, inclusive.
What are the depths of the nodes containing 1, 4, and 8?
What are the heights of the subtrees rooted at the nodes containing 1, 4, and 8?
What is the height of this total tree?
Which of the above answers would change if a new 16th node was added anywhere in the tree?