Question: gentamicin belongs to which class of antibacterial agents
[{'answer': 'aminoglycoside', 'provenance': [{'wikipedia_id': '254717', 'title': 'Gentamicin', 'start_paragraph_id': 2, 'start_character': 322, 'end_paragraph_id': 2, 'end_character': 336, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '254717', 'title': 'Gentamicin', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 441, 'bleu_score': 0.747223661716496, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14384301382109728885}, 'section': 'Section::::Abstract.'}]}]