**Answer: A**

Balancing of a BST is important to give the desired *O(log n)*
search time. If the tree is unbalanced, search time could be
as bad as *O(n)*. While *O(n)* is not always bad, we
expect a lookup table to have a time of *O(1)* or *O(log n)*
because lookup is done frequently, often in a loop.
(Unless the table is known to be small, in which *O(n)* is okay.)