What will the following code snippet work? If not, what

What will the following code snippet work? If not, what will be the error?

function test(p) 
{ 
    for (; p.next; p = p.next) ;
    return p;
}

1. No, this will not iterate
2. No, this will result in a runtime error with the message “Cannot use Linked List”
3. No, this will throw an exception as only numerics can be used in a for loop
4. Yes, this will work
5. None of these

The above code uses a for loop to traverse a linked list data structure and return the last object in the list. This will perfectly work.