While inserting the elements 71, 65, 84, 69, 67, 83 in an empty binary search tree (BST) in the sequence shown, the element in the lowest level is

Let us trace the insertion of elements into an initially empty Binary Search Tree (BST):

1. Insert 71: becomes the root at Level 0.

2. Insert 65: $65 < 71$, inserted as the left child of $71$ (Level 1).

3. Insert 84: $84 > 71$, inserted as the right child of $71$ (Level 1).

4. Insert 69: $69 < 71$ and $69 > 65$, inserted as the right child of $65$ (Level 2).

5. Insert 67: $67 < 71$, $67 > 65$, and $67 < 69$, inserted as the left child of $69$ (Level 3).

6. Insert 83: $83 > 71$ and $83 < 84$, inserted as the left child of $84$ (Level 2).

The levels containing the nodes are:

• Level 0: $71$

• Level 1: $65, 84$

• Level 2: $69, 83$

• Level 3: $67$

The element at the lowest (deepest) level is 67.