Question: which part of a flower receives pollen grains during pollination
[{'answer': 'stigma ,', 'provenance': [{'wikipedia_id': '233609', 'title': 'Pollination', 'start_paragraph_id': 3, 'start_character': 101, 'end_paragraph_id': 3, 'end_character': 114, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]