问题：

[单选]

public class A extends Thread { 
A（） { 
setDaemon（true）； 
} 
public void run（） { 
（new B（））.start（）； 
try { 
Thread.sleep（60000）； 
} catch （InterruptedException x） {} 
System.out.println（“A done”）； 
} 
class B extends Thread { 
public void run（） { 
try { 
Thread.sleep（60000）； 
} catch （InterruptedException x） {} 
System.out.println（“B done”）； 
} 
} 
public static void main（String[] args） { 
（new A（））.start（）； 
} 
}  
What is the result？（）  

A .  A done
B .  B done
C .  A done B done
D .  B done A done
E .  There is no exception that the application will print anything.
F .  The application outputs “A done” and “B done”， in no guaranteed order.