java

Assume the following method is within the SingleLinkedList class, what does it do? public void Undefined(E item1, E item2) { Node ptr = head: while (ptr != null) if(ptr.data.equals(itemt)) head = new Node(item2, head): return; 3 ptruptr.next: A Adds a node before the first node with its data as item2, if item1 exists anywhere in the list B Adds a node before the first node with its data as item2, if itemtexists as data of the first node in the list Adds a node after the last node with its data as item2, if itemtexists anywhere in the list D Adds a node after the last node with its data as item2, if itemtexists as data of the first node in the list