複選題40. Which of the following statem ents are true? (A) An insertion in AVL tree requires Ω(logn) single- and double-rotations in the worst case. (B) An insertion in AVL trce requires O(1) single- and double-rotations in the worst case. (C) A deletion in AVL tree requires Ω(logn) single- and double-rotations in the worst case. (D) Adeletion in AVL tree requires O(1) singie- and double-rotations in the worst case. (E) There is no red left child in AA tree.