Question: who was the u.s. military officer that was at the head of the iranian arms deals
[{'answer': 'Oliver North', 'provenance': [{'wikipedia_id': '14787', 'title': 'Iran–Contra affair', 'start_paragraph_id': 3, 'start_character': 69, 'end_paragraph_id': 3, 'end_character': 81, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '14787', 'title': 'Iran–Contra affair', 'start_paragraph_id': 36, 'start_character': 0, 'end_paragraph_id': 36, 'end_character': 1791, 'bleu_score': 0.977274894612373, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17217188967699643779}, 'section': 'Section::::Arms sales to Iran.:Modifications in plans.\n'}]}]