Question: who is the head coach of the raiders
[{'answer': 'Jon Gruden', 'provenance': [{'wikipedia_id': '16966469', 'title': 'List of Oakland Raiders head coaches', 'start_paragraph_id': 1, 'start_character': 781, 'end_paragraph_id': 1, 'end_character': 791, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]