Question: when did the celebration of mother's day began
[{'answer': 'the early 20th century', 'provenance': [{'wikipedia_id': '46276', 'title': "Mother's Day", 'start_paragraph_id': 2, 'start_character': 88, 'end_paragraph_id': 2, 'end_character': 110, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '46276', 'title': "Mother's Day", 'start_paragraph_id': 2, 'start_character': 4, 'end_paragraph_id': 2, 'end_character': 567, 'bleu_score': 0.878997440250826, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5103084603387449362}, 'section': 'Section::::Abstract.'}]}]