Question: when did blood transfusions become safer and why
[{'answer': '1901', 'provenance': [{'wikipedia_id': '88857', 'title': 'Blood transfusion', 'start_paragraph_id': 83, 'start_character': 17, 'end_paragraph_id': 83, 'end_character': 21, 'bleu_score': 1.0, 'section': 'Section::::History.:20th century.\n'}]}, {'provenance': [{'wikipedia_id': '88857', 'title': 'Blood transfusion', 'start_paragraph_id': 83, 'start_character': 0, 'end_paragraph_id': 83, 'end_character': 180, 'bleu_score': 0.9364250605898111, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9374357334596675523}, 'section': 'Section::::History.:20th century.\n'}]}]