6. (5 points) Provide answers to the following 5 questions: (a) (1 point) What is the worst case time complexity of finding the minimum element in a max-heap? (b) (1 point) What is the minimum number of nodes that can take place in a binary heap of height 4? (c) (1 point) What is the maximum number of nodes that can take place in a binary heap of height 4? (d) (1 point) What is the minimum height of an AVL tree that has 15 nodes? (e) (1 point) What is the maximum height of an AVL tree that has 15 nodes