void doo(node *root) if(root !=0) { nodecint>*p=root; while(root->next!=0) root=root->next; p->data=root->data; } What is this code do? O a. set the first item in the linked list as the last item O b. doesn't do anything because the root parameter is passed by value O c. change the root item in the binary tree with the farthest leaf item O d. swap the first item with the last item in the linked list