(A) (n+m) log2 n ….
If names are encountered in random order, the average length of a path in the tree will be proportional to log n, where n is the number of names....
Therefore each search follows one path from the root, the expected time needed to enter n names and make m inquiries is proportional to (n + m) log n ….
If n is greater than about 50, there is a clear advantage to the binary search tree over the linked list and probably over the linked self-organizing list….