Question: who were the architects that designed and built big ben
[{'answer': 'Augustus Pugin', 'provenance': [{'wikipedia_id': '7290308', 'title': 'Big Ben', 'start_paragraph_id': 2, 'start_character': 26, 'end_paragraph_id': 2, 'end_character': 40, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]