Consider the following function that takes reference to head of a Doubly Linked List as parameter. Assume that a node of doubly linked list has previous pointer as prev and next pointer as next.

Assume that reference of head of following doubly linked list is passed to above function 1 2 3 4 5 6.

What should be the modified linked list after the function call?

A. 2 1 4 3 6 5 

B. 5 4 3 2 1 6.

C. 6 5 4 3 2 1.

D. 6 5 4 3 1 2

void fun (struct node **head_ref) { } struct node *temp = NULL; struct node *current = *head_ref; while (current != NULL) { } temp = current->prev; current->prev = current->next; current->next = temp; current current->prev; if (temp != NULL ) *head_ref = temp->prev;