Question: which component of the continental margin has the greatest economic and political significance
[{'answer': 'the continental shelf', 'provenance': [{'wikipedia_id': '4579350', 'title': 'Continental margin', 'start_paragraph_id': 1, 'start_character': 327, 'end_paragraph_id': 1, 'end_character': 348, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '4579350', 'title': 'Continental margin', 'start_paragraph_id': 10, 'start_character': 0, 'end_paragraph_id': 10, 'end_character': 241, 'bleu_score': 0.948006874591591, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14683747806660256336}, 'section': 'Section::::Economic significance.\n'}]}]