Question: who wrote the national anthem of south africa
[{'answer': 'Enoch Sontonga', 'provenance': [{'wikipedia_id': '30944', 'title': 'National anthem of South Africa', 'start_paragraph_id': 8, 'start_character': 422, 'end_paragraph_id': 8, 'end_character': 436, 'bleu_score': 1.0, 'section': 'Section::::History.:Background.\n'}]}, {'answer': 'C.J. Langenhoven'}]