Question: what are three largest trade unions in south africa
[{'answer': 'African National Congress', 'provenance': [{'wikipedia_id': '5944228', 'title': 'Trade unions in South Africa', 'start_paragraph_id': 2, 'start_character': 332, 'end_paragraph_id': 2, 'end_character': 357, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'South African Communist Party', 'provenance': [{'wikipedia_id': '5944228', 'title': 'Trade unions in South Africa', 'start_paragraph_id': 2, 'start_character': 372, 'end_paragraph_id': 2, 'end_character': 401, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Congress of South African Trade Unions'}, {'provenance': [{'wikipedia_id': '5944228', 'title': 'Trade unions in South Africa', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 407, 'bleu_score': 0.970362113628587, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7086260050101613438}, 'section': 'Section::::Abstract.'}]}]