Question: who suggested class conflict drives human history and is at the core of human progress
[{'answer': 'Marx', 'provenance': [{'wikipedia_id': '46399149', 'title': 'Historical materialism', 'start_paragraph_id': 1, 'start_character': 121, 'end_paragraph_id': 1, 'end_character': 125, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]