Question: what type of plate boundary is found in the middle of the atlantic ocean
[{'answer': 'constructive plate boundary', 'provenance': [{'wikipedia_id': '145705', 'title': 'Mid-Atlantic Ridge', 'start_paragraph_id': 1, 'start_character': 81, 'end_paragraph_id': 1, 'end_character': 108, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '145705', 'title': 'Mid-Atlantic Ridge', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 791, 'bleu_score': 0.8291462181489371, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17445450259351052864}, 'section': 'Section::::Abstract.'}]}]