Question: who led the first portuguese voyage to benin
[{'answer': 'Joao Afonso de Aveiro', 'provenance': [{'wikipedia_id': '25649488', 'title': 'Kingdom of Benin', 'start_paragraph_id': 11, 'start_character': 424, 'end_paragraph_id': 11, 'end_character': 445, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '25649488', 'title': 'Kingdom of Benin', 'start_paragraph_id': 11, 'start_character': 0, 'end_paragraph_id': 11, 'end_character': 528, 'bleu_score': 0.9106019131024261, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7453934037672013728}, 'section': 'Section::::History.\n'}]}]