Answer plz?

5. What is the worst-case running time of an algorithm that search for an element in a Binary Search Tree? (2 points) (a) O(1) (b) O(log n) (c) On) (d) O(n) 6. What is the worst-case running time of an algorithm to push an element to a stack ? (2 points) (a) O(1) (b) O(log n) (c) O(n) (d) O(n) 7. What is the worst-case running time of binary search algorithm on an ordered elements stored in an array? (2 points) (a) O(1) (b) O(log n) (c) O(n) (d) (n) 8. What is the worst-case running time of search algorithm on an ordered elements stored linked list? (2 points) (a) O(1) (b) O(log n) (c) O(n) (d) (n) 9. how many edges in a complete digraph with 100 nodes? (2 points) (a) 99 (b) 100 (c) 9900 (d) 10000