Which of the Following Statements About a Binary Search Tree

Which of the following statements about a binary search tree is correct?

A) Adding elements that are already sorted will result in a balanced binary search tree.
B) Nodes must be moved when a node is removed from the middle of a subtree.
C) The speed of inserting or removing a node is dependent on the shape of the tree.
D) The speed of inserting or removing a node is dependent on the number of subtrees.