Question: what's the closest habitable planet to earth
[{'answer': 'Proxima Centauri', 'provenance': [{'wikipedia_id': '33179483', 'title': 'List of nearest terrestrial exoplanet candidates', 'start_paragraph_id': 7, 'start_character': 99, 'end_paragraph_id': 7, 'end_character': 115, 'bleu_score': 1.0, 'section': 'Section::::Exoplanets discovered (incomplete).\n'}]}, {'provenance': [{'wikipedia_id': '33179483', 'title': 'List of nearest terrestrial exoplanet candidates', 'start_paragraph_id': 7, 'start_character': 0, 'end_paragraph_id': 7, 'end_character': 951, 'bleu_score': 0.9476974047280211, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4861831153170720940}, 'section': 'Section::::Exoplanets discovered (incomplete).\n'}]}]