Question: what is the devils tower made out of
[{'answer': 'igneous rock', 'provenance': [{'wikipedia_id': '272986', 'title': 'Devils Tower', 'start_paragraph_id': 1, 'start_character': 92, 'end_paragraph_id': 1, 'end_character': 104, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '272986', 'title': 'Devils Tower', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 410, 'bleu_score': 0.8776763543030001, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10722380135755032001}, 'section': 'Section::::Abstract.'}]}]