问题：

[单选]

import java.util.*； 
public class LetterASort { 
public static void main（String[] args） { 
ArrayList strings = new ArrayList（）； 
strings.add（‟aAaA”）； 
strings.add（”AaA”）；
strings.add（‟aAa”）； 
strings.add（”AAaa”）； 
Collections.sort（strings）； 
for （String s： strings） { System.out.print（s + “ “）； } 
} 
} 
What is the result？（） 

A .  Compilation fails.
B .  aAaA aAa AAaa AaA
C .  AAaa AaA aAa aAaA
D .  AaA AAaa aAaA aAa
E .  aAa AaA aAaA AAaa
F .  An exception is thrown at runtime.