Respuesta :
The answer would be Where have you been mother? This is because if you replace mother with a proper pronoun such as Jean (a name) the sentence wouldn't change. For instance Where have you been Jean? See? The sentence didn't change. All the other sentences have my in front of mother, so you couldn't replace a name with it. Your mother doesn't belong to you, so you can't replace the mother in that case with a proper pronoun.
The sentence "Where have you been, mother?", the word mother is not a possessive pronoun therefor it should be capitalized. "Where have you been, Mother?", is the correct form of this sentence. I hope I helped :).