Question: who won the wwe elimination chamber in 2018
[{'answer': 'Roman Reigns', 'provenance': [{'wikipedia_id': '55948000', 'title': 'Elimination Chamber (2018)', 'start_paragraph_id': 2, 'start_character': 91, 'end_paragraph_id': 2, 'end_character': 103, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '55948000', 'title': 'Elimination Chamber (2018)', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 777, 'bleu_score': 0.964583525681703, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10179662965197665771}, 'section': 'Section::::Abstract.'}]}]