Question: what is the world most common blood type
[{'answer': 'O+', 'provenance': [{'wikipedia_id': '40950178', 'title': 'Blood type distribution by country', 'start_paragraph_id': 0, 'start_character': 2, 'end_paragraph_id': 0, 'end_character': 3, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]