现自： 
1．  interface Color {  }     
2. interface Weight  {  }     
3．  //insert code here   
和以下足六个声明： 
class Boat extends Color， extends Weight  {  }    
class Boat extends Color and Weight  {  }     
class Boat extends Color， Weight  {  } 
class Boat implements Color，  implements Weight  {  }    
class Boat implements Color and Weight  {  }     
class Boat implements Color， Weight  {  }   
分别插入到第3行，有多少行可以编译？ （） 

A.  0
B.  1
C.  2
D.  3