Where is “BERLIN” ? Without “BERLIN” in the text as Mr Sanborn has said himself over and over again, your answer is incomplete/has errors. By saying that “BERLIN” is not in the text then you are saying that Mr Sanborn is lying????
If you are convinced that your K4 answer is correct then why not post some of your workings. You do not have to post all of them just some so to get some feedback.