11. rbo = new ReallyBigObject（）； 
12. // more code here 
13. rbo = null； 
14. /* insert code here */ 
Which statement should be placed at line 14 to suggest that the virtual machine expend effort toward recycling the memory used by the object rbo？（） 

11. public void genNumbers（） { 
12. ArrayList numbers = new ArrayList（）； 
13. for （int i=0； i<10； i++） { 
14. int value = i * （（int） Math.random（））； 
15. Integer intObj = new Integer（value）； 
16. numbers.add（intObj）； 
17. } 
18. System.out.println（numbers）； 
19. } 
Which line of code marks the earliest point that an object referenced by intObj becomes a candidate for garbage collection？（） 

class Foo { 
private int x； 
publicFoo（intx） {this.x=x； } 
public void setX（ int x） { this.x = x； } 
public int getX（） { return x； } 
}  
public class Gamma { 
static Foo fooBar（ Foo foo） { 
foo = new Foo（ 100）； 
return foo； 
} 
public static void main（ String[] args） { 
Foo foo = new Foo（ 300）； 
System.out.print（ foo.getX（） + “-“）； 
Foo fooFoo = fooBar（ foo）； 
System.out.print（ foo.getX（） + “-“）； 
System.out.print（ fooFoo.getX（） + “-“）； 
foo = fooBar（ fooFoo）； 
System.out.print（ foo.getX（） + “-“）； 
System.out.prmt（ fooFoo.getX（））； 
} 
} 
What is the output of this program？（）

10. class Inner { 
11. private int x； 
12. public void setX（ int x） { this.x = x； } 
13. public int getX（） { return x； } 
14. } 
15. 
16. class Outer { 
17. private Inner y； 
18. public void setY（ Inner y） { this.y = y； } 
19. public Inner getY（） { return y； } 
20. } 
21. 
22. public class Gamma { 
23. public static void main（ String[] args） {
24. Outer o = new Outer（）；
25. Inner i = new Inner（）； 
26.int n=10； 
27. i.setX（n）； 
28. o.setY（i）； 
29. // insert code here 
30. System.out.println（ o.getY（）.getX（））； 
31. } 
32. } 
Which three code fragments， added individually at line 29， produce the output 100？（）