Question: which metal is used as a thin film on sweets
[{'answer': 'silver', 'provenance': [{'wikipedia_id': '1581831', 'title': 'Vark', 'start_paragraph_id': 1, 'start_character': 30, 'end_paragraph_id': 1, 'end_character': 36, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'gold', 'provenance': [{'wikipedia_id': '1581831', 'title': 'Vark', 'start_paragraph_id': 1, 'start_character': 139, 'end_paragraph_id': 1, 'end_character': 143, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1581831', 'title': 'Vark', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 887, 'bleu_score': 0.809531657332578, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9818829006945159377}, 'section': 'Section::::Abstract.'}]}]