Question: who sang as maria in west side story
[{'answer': 'Marni Nixon', 'provenance': [{'wikipedia_id': '477971', 'title': 'Marni Nixon', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 11, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '477971', 'title': 'Marni Nixon', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 368, 'bleu_score': 0.5329637076651701, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5892052792401134961}, 'section': 'Section::::Abstract.'}]}]