1. This partial class definition can be used to implement a Linked List of Student object. Which of the following code snippets would properly complete method isEmpty, which should return true is the list contains no objects.

a) if (first == null) return first;

b) return first == null;

c) return first;

d) if (first != null) return true;

e) if (next == null) return true;

public class Student f private Student next private String name, id: public Student (String n, String ) name = n; idi next = null; public void setNext (Student s) t next S: public Student getNext( f return next: public class LinkList private Student first; public LinkList O first = null; public boolean isEmpty) //returns true if the list is empty, false if it has at least one element public void push (Student s)t //inserts the element in the front of the list