9. Given the following AVL tree what is the balanced at node "150"? (2 Marks) 100 (50 75 (76 150 (125 (124 (130) (131 (74 (73) b. 2 c.3 d. 4 10. Given the following binary search tree. If we delete root node "20", then which node from the left sub-tree can replace the root node "20"? (1 Mark) b. 37 c. 16 d. 18 11. Given the following AVL tree. Insert the numbers in sequence (0, 3, 4 and 6) in the AVL tree. Which node will be at the Root node after inserting the above numbers? (3 Marks) a 2 b. 4 c. 6 d. 7