Which two statements, added independently at the beginning of the program, allow the code to compile?

/* Missing statements ? */
public class NewArrayList extends java.util.ArrayList {
    public static void main(String[] args) {
        java.util.ArrayList list = new java.util.ArrayList();
        list.add("Hello");
        Collections.sort(list);
    }

    public void clearList() {
        HashSet set = new HashSet();
        set.clear();
    }
}

1. No statement is required
2. import java.util.*;
3. import java.util.Hash*;
4. import java.util.ArrayList;
5. import java.util.Collections;
6. import java.util.HashSet;
Choose the correct answer: