单项选择题

现有:  
1. interface Animal {   
2.   void eat();  
3.  }   
4.  
5. // insert code here   
6.  
7. public class HouseCat implements Feline {   
8.   public void eat() { }  
9. }  
和以下三个接口声明:  
interface Feline extends Animal { }   
interface Feline extends Animal { void eat(); }    
interface Feline extends Animal { void eat() { } }   
分别插入到第 5 行,有多少行可以编译?()  

A. 0
B. 1
C. 2
D. 3