Question: the green in nigeria flag stand for what
[{'answer': "Nigeria 's natural wealth", 'provenance': [{'wikipedia_id': '459277', 'title': 'Flag of Nigeria', 'start_paragraph_id': 3, 'start_character': 24, 'end_paragraph_id': 3, 'end_character': 48, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]