Consider unsorted doubly linked list data structure containing n items. For decrease key operation a pointer is provided to the record on which the operation is performed. An algorithm performs the following operations on the list in this order: sqrt(n) insert operations, o(nlogn) decrease key and O(n) find operations. What is the time complexity of all these operations put together?
(a) O(n)
(b) O(n2)
(c) O(n2logn)
(d) O(sqrt(n))