Linked List
i. root(n) insert operations = $O(root(n))$ we can insert at the beginning of the linked list.
ii. O(nlogn) decrease key operation = as it's not given that linked is sorted, Hence, O(1) needs for one decrease key operation, total T.C needed is $O(nlogn)$.
iii. n find operations, each needs O(n), total cost $O(n^2)$
Max if these three is $O(n^2)$.
Hence, correct answer is (B).