Question: who sings the christmas song all i want for christmas is you
[{'answer': 'Mariah Carey', 'provenance': [{'wikipedia_id': '1822980', 'title': 'All I Want for Christmas Is You', 'start_paragraph_id': 1, 'start_character': 98, 'end_paragraph_id': 1, 'end_character': 110, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'American singer and songwriter Mariah Carey'}, {'provenance': [{'wikipedia_id': '1822980', 'title': 'All I Want for Christmas Is You', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 426, 'bleu_score': 0.8999692131593551, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6942587719246803140}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1822980', 'title': 'All I Want for Christmas Is You', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 0, 'bleu_score': 1.0, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6942587719246803140}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1822980', 'title': 'All I Want for Christmas Is You', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['"All I Want for Christmas Is You" is a Christmas song performed by American singer and songwriter Mariah Carey', '"All I Want for Christmas Is You" is a Christmas song performed by American singer and songwriter Mariah Carey.', '"All I Want for Christmas Is You" is a Christmas song performed by American singer and songwriter Mariah Carey']}}]}]