A. The value of the left child should be less than the root node
B. The value of the right child should be greater than the root node.
C. The left and right sub trees should also be a binary search tree
D. None of the above

Solution

D. None of the above

Explanation

All the three options, i.e., a, b and c are true for the binary search tree. In binary search tree, the left child should be less than the root node and the right child should be greater than the value of the root node.