複選題38. Consider a binary scarch tree that results from successively inserting keys 2, 8, 9, 1, 5. 7, 6, 3, 4 into an initially empty tree. Which of the following statements are true? (A) The tree height is 4. (B) Key 8 is prior to key 3 in terms of pre-order traversal. (C) Key 2 is prior to key 7 in terns of post-order traversal. (D) Key 4 is prior to key 5 in terms of in-order traversal. (E) Key 3 and key 9 are siblings.