Question: where is the first caucus held for each presidential campaign
[{'answer': 'Iowa', 'provenance': [{'wikipedia_id': '185311', 'title': 'United States presidential primary', 'start_paragraph_id': 3, 'start_character': 429, 'end_paragraph_id': 3, 'end_character': 433, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]