Question: who discovered law of conservation of electric charge
[{'answer': 'William Watson', 'provenance': [{'wikipedia_id': '3094621', 'title': 'Charge conservation', 'start_paragraph_id': 5, 'start_character': 60, 'end_paragraph_id': 5, 'end_character': 74, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'answer': 'Benjamin Franklin', 'provenance': [{'wikipedia_id': '3094621', 'title': 'Charge conservation', 'start_paragraph_id': 5, 'start_character': 120, 'end_paragraph_id': 5, 'end_character': 137, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'answer': 'Michael Faraday', 'provenance': [{'wikipedia_id': '3094621', 'title': 'Charge conservation', 'start_paragraph_id': 5, 'start_character': 196, 'end_paragraph_id': 5, 'end_character': 211, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}]