Question: what was the lower class in rome called
[{'answer': 'Proletarii', 'provenance': [{'wikipedia_id': '3453921', 'title': 'Social class in ancient Rome', 'start_paragraph_id': 16, 'start_character': 442, 'end_paragraph_id': 16, 'end_character': 452, 'bleu_score': 1.0, 'section': 'Section::::Property-based classes.\n'}]}]