Question: who enforces the controlled substances act of 1970
[{'answer': 'Drug Enforcement Administration', 'provenance': [{'wikipedia_id': '7727', 'title': 'Controlled Substances Act', 'start_paragraph_id': 2, 'start_character': 152, 'end_paragraph_id': 2, 'end_character': 183, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '7727', 'title': 'Controlled Substances Act', 'start_paragraph_id': 25, 'start_character': 0, 'end_paragraph_id': 25, 'end_character': 650, 'bleu_score': 0.9810405040225261, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9589664091633432300}, 'section': 'Section::::Enforcement authority.\n'}]}]