Question: who was the first ruler of pala dynasty
[{'answer': 'Gopala', 'provenance': [{'wikipedia_id': '1193780', 'title': 'Pala Empire', 'start_paragraph_id': 1, 'start_character': 419, 'end_paragraph_id': 1, 'end_character': 425, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1193780', 'title': 'Pala Empire', 'start_paragraph_id': 9, 'start_character': 0, 'end_paragraph_id': 9, 'end_character': 1154, 'bleu_score': 0.9894455409323081, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15894528183501362724}, 'section': 'Section::::History.:Establishment.\n'}]}]