Question: who developed staining method for differentiating between groups of bacteria
[{'answer': 'Hans Christian Gram', 'provenance': [{'wikipedia_id': '12935', 'title': 'Gram stain', 'start_paragraph_id': 1, 'start_character': 234, 'end_paragraph_id': 1, 'end_character': 253, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '12935', 'title': 'Gram stain', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 282, 'bleu_score': 0.9560167778278961, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 698924588996003457}, 'section': 'Section::::Abstract.'}]}]