Question: in the tv series buffy the vampire slayer what is buffy's last name
[{'answer': 'Summers', 'provenance': [{'wikipedia_id': '47542', 'title': 'Buffy the Vampire Slayer', 'start_paragraph_id': 2, 'start_character': 124, 'end_paragraph_id': 2, 'end_character': 131, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '47542', 'title': 'Buffy the Vampire Slayer', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 696, 'bleu_score': 0.9243004410966761, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11606973981439533432}, 'section': 'Section::::Abstract.'}]}]