Question about class and interface

[Scott Xia]

question under:
interface Foo{
int k=0;
}
public class Test implements Foo{
public static void main(String args[]){
int i;
Test test=new Test();
i=test.k;
i=Test.k;
i=Foo.k;
}
}
Which statement is true?
A. Compilation succeeds
B. An error at line 2 causes compilation to fail
C. An error at line 9 causes compilation to fail
D. An error at line 10 causes compilation to fail
E. An error at line 11 causes compilation to fail
the answer is A
i do not understand why ?

[Panday Manako]

fields in interfaces are automatically static and final

[Scott Xia]

thank you