The numbers on the left margin denote line numbers. line# 01 class LL_node { 02 int val; 03 LL_node next; 04 public LL_node (int n) { 05 val = n; 06 next = null; 07 } 08 public void set_next (LL_node...

The numbers on the left margin denote line numbers.

line#
01 class LL_node {
02     int val;
03     LL_node next;
04     public LL_node (int n) {
05         val = n;
06         next = null;
07     }
08     public void set_next (LL_node nextNode) {
09         next = nextNode;
10     }
11     public LL_node get_next () {
12         return next;
13     }
14     public void set_value (int input) {
15         val = input;
16     }
17     public int get_value () {
18         return val;
19     }
20 }
21 public class LL {
22     protected LL_node head;
23     protected LL_node tail;
24     public LL () {
25         head = null;
26         tail = null;
27     }
28     public int append (int n) {
29         if (head == null) {
30             head = new LL_node(n);
31             tail = head;
32         } else {
33             LL_node new_node;
34             new_node = new LL_node(n);
35             tail.set_next (new_node);
36             tail = new_node;
37         }
38         return n;
39     }
40 }

which the following statement is true (it can be more than one correct answers